Get help on our basic JavaScript and Algorithms Challenges. If you are posting code that is large use Gist - https://gist.github.com/ paste the link here.
@domuttel No.
You're supposed to re-assign the result variable.
But, meh.
Oh I see then so I guess I gotta get more smarts together
lol
What's the point of doing this...
haha
result = thing.thinger;
return result;
Why not just do...
return thing.thinger;
As to have clear code?
The top one is not clearer than the bottom one.
Hmmmmm...
@domuttel Maybe it is clearer if the process was larger.
But, when you do returns the way the top one is done you have to go...
No I think I see what you are saying
Okay, we're returning result.. Let's look up and see what result is again.
Okay. That's result. So, that's we're returning that thing.
In a small block of code it is quite pointless.
I see
BUT! If you get into a function that calls another function .. Maybe it would be better.
Right! I totally see wat you are saying
Every challenge is a little different but we usually see/play around with the structure, variable assignment, etc. The setup isnt alway perfect and there are many ways to get a solution. With every challenge you get more insight and can probably get an answer cleaner, quicker, etc.
@tommygebru That's right.
You should see how I solved some of the challenges when I started working lessons.
I went back through and was all... Damn I did that the hard way.
I think for one challenge I took 20 lines of code down to 2.
Red light, Green light, refactor
Though... Seek and Destroy is still my original code.. I think.
hahahaha
Oh,.... I did refactor that one.
I dig
That challenge SUCKS!
Anyhow!
The one I was working on?
@revisualize
@dmcfaddengalway did you figure it out?
What problem are you working on?
having a problem with----Adding a default option in Switch statements
@dmcfaddengalway I work mine out on a text editor to double check stuff
Although I just got stumped
switch (val) {
case 1:
if (val === "a") {
answer = "apple";
}
break;
case 2:
if (val === "b") {
answer = "bird";
}
break;
case 3:
if (val === "c") {
answer = "cat";
}
break;
default:
answer = "stuff";}
put the break in the if
try that already
actually no, you do case "a"
so the if is not necessary
yea that works, so the case value and the value im checking has to be the same type?
not in javascript no
everything is just a var, no ints, no chars, no bools etc
switch is just switch variable
saves a bunch of if statements
function slasher(arr, howMany) {
var holderArray = [];
var count = 0;
for (i = count; i === 0; i++) {
holderArray.splice(arr.slice(arr[0], howMany));
}
return holderArray;
}
slasher([1, 2, 3], 2);
//or for (i=count;i = arr.length, i++)I right?
@domuttel return lagest numbers in array
@cdomiano Yes, the test is false so the loop doesn't run. Are you sure you even need a loop?
I haven't considered it, I guess I wan't think straight after using loops for every challenge so far. What is a good direction to go? @sjames1958gm
@cdomiano If you read the docs on slice - a single slice will do the trick here
I have a problem with writing escape sequences
I just did, right direction? @sjames1958gm
function slasher(arr, howMany) {
arr.slice(0, howMany);
return arr;
}
slasher([1, 2, 3], 2);
It's not doing anything, do I need to splice it to array after slicing it?
@cdomiano Does slice modify the array in place?
@cdomiano some functions mutate the array, such as push, pop, etc. Some only return a new value.
@cdomiano maybe you should
return arr.slice(0, howMany); instead of just arr?
@cdomiano oh no I think I'm wrong
@cdomiano sorry
@dmcfaddengalway why dont you use a texteditor and the console?
that will def work with console.log();
@OleksandrNedobitkov What do you have so far
I'm not sure @revisualize It looks like it modifies the end of the array
function slasher(arr, howMany) {
// arr.slice(0);
// arr= arr.splice()
return arr.slice(0, howMany);//returns 1,2 not 3
}
slasher([1, 2, 3], 2);
@cdomiano You can use a site like repl.it or jsbin.com to experiment - or just open devtools console
@cdomiano So the first parameter is where to start the slice
@cdomiano or you cant just use splice
Hello world!
welcome to FreeCodeCamp @airborneprayer!
I'm working on the tic tac toe project and i cant figure out how to make the X's and O's bigger in the html table im using as a playing board without the table itself becoming bigger, help?
function slasher(arr, howMany) {
arr.slice(0);
arr= arr.splice(howMany);
return arr
;
}
slasher([1, 2, 3], 2);cdomiano sends brownie points to @skidle and @revisualize and @sjames1958gm :sparkles: :thumbsup: :sparkles:
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@cdomiano arr.slice(0) returns the whole array - it does nothing to the arr variable.
Then arr.slice(howMany) sliced off the end which you stored in arr
Then arr.slice(howMany) sliced off the end which you stored in arr
I'm new to this guys I need big time help.
This is the place for big time help :)
Hi! anyone able to take a look at this and help me figure out how to put the actual generated quote into the box? http://codepen.io/emmalee113/pen/WojpVY
I'm wanting to know how to convert celsius to fahrenheit
//Age in minutes and seconds
function convertToF(celsius) {
var fahrenheit;
// Only change code below this line
// Only change code above this line
return fahrenheit;
}
// Change the inputs below to test your code
convertToF(30);
some people use api, i hard coded a bunch in @emmalee113
@airborneprayer your var fahrenheit should equal celsius parameter * something something
@airborneprayer they have instructions for conversion in the task
@ylu01 if you look under the tan colored box, i have a generator which is showing quote1, quote 2, etc randomly. that part i have figured out. but how do i move that into the box where i have the text "quote"?
@emmalee113 if the box is a div you can just next them in that
@emmalee113 Your HTML has a problem - it should be class="quotebox"
Then you can
Then you can
document.querySelector(".quotebox").textContent = Quotation[whichQuotation]
@ylu01 nest all my javascript in the div?
@sjames1958gm would that simply go in my <h3> ?
@airborneprayer When the function is called (e.g. convertToF(30)) the variable/parameter celsius will contain the value to be converted (e.g. 30) you should use the provided conversion formula and this variable celsius to set the fahrenheit parameter
@emmalee113 yes
Seek and Destroy bonfire, can anyone guide me please?
@marioecg Filter out the unwanted numbers
Array.filter() method
Array.filter() method
@marioecg https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter the first example shows well what you need to do.
@JohnnyBizzel @lbg232 same as with the Falsy bonfire?
@emmalee113 I would put a Div around the H3 you are putting the quote into. As suggested above.
@marioecg Can't remember that one sorry. - just checked. Yes that will work.
@JohnnyBizzel thanks
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i dont understand .keys() at all
can someone help me udnerstand
@marioecg https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/this sorry, you need that one too
@JohnnyBizzel so i have this:
<div>
<h3 class = quotebox>
quote
</h3>
</div>
@emmalee113 Using an ID on the div you can control the style more easily. And also access it with jQuery
@lbg232 thnks
@marioecg if you scroll up this chat I was working on it at 20:13 and somebody explained to me.
In: Testing Objects for Properties... Do I need a for loop?
@lbg232 alright, thanks
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an if else should do- I think
function checkObj(checkProp) {
// Your Code Here
if ( checkProp !== true ) {
return "Not Found";
} else {
return myObj[checkProp][0];
}
}
@emmalee113 was helping my dad carrying stuff, your <style> stuff should go under the css part, the <p> tag that says quote, should be in a div which would be your box
@domuttel what's your query?
wonder why [0] at the end @domuttel
also probably u should use hasOwnProperty
also probably u should use hasOwnProperty
this is mine
@domuttel
myObj.hasOwnProperty(...)
myObj.hasOwnProperty(...)
@ylu01 thanks ! I'm gonna take a deeper look at how you did yours. i was able to figure it out but want to see different ways
emmalee113 sends brownie points to @ylu01 :sparkles: :thumbsup: :sparkles:
:warning: could not find receiver for ylu01
np
Hello, it's first time when I'm writing here.. I would love to ask you about her with target 145 escape sequences in strings
Can anyone tell me why this code isn't working for mouseup/mousedown in jQuery? It works in part, in that it toggles, but not on the same mouse-click
$("#g").on("mousedown", function() {
$("#g").toggleClass('fullGreen');
}).on("mouseup", function() {
$(this).toggleClass('n-green');
});
@ylu01 "China - Donald Tromp" X,DDD
tramp*
Here's the codepen for anyone who can help
https://codepen.io/antiaccess/pen/wogRwp
https://codepen.io/antiaccess/pen/wogRwp
@lbg232 trump*
try clicking on
green
Hi everyone. I just finished a javascript beginner guide. Honestly , I don't know how to use that syntax all in one piece like this guy did :
// Set the number of snowflakes (more than 30 - 40 not recommended)
var snowmax=35
// Set the colors for the snow. Add as many colors as you like
var snowcolor=new Array("#aaaacc","#ddddFF","#ccccDD")
// Set the fonts, that create the snowflakes. Add as many fonts as you like
var snowtype=new Array("Arial Black","Arial Narrow","Times","Comic Sans MS")
// Set the letter that creates your snowflake (recommended:*)
var snowletter="*"
// Set the speed of sinking (recommended values range from 0.3 to 2)
var sinkspeed=0.6
// Set the maximal-size of your snowflaxes
var snowmaxsize=22
// Set the minimal-size of your snowflaxes
var snowminsize=8
// Set the snowing-zone
// Set 1 for all-over-snowing, set 2 for left-side-snowing
// Set 3 for center-snowing, set 4 for right-side-snowing
var snowingzone=3
///////////////////////////////////////////////////////////////////////////
// CONFIGURATION ENDS HERE
///////////////////////////////////////////////////////////////////////////
// Do not edit below this line
var snow=new Array()
var marginbottom
var marginright
var timer
var i_snow=0
var x_mv=new Array();
var crds=new Array();
var lftrght=new Array();
var browserinfos=navigator.userAgent
var ie5=document.all&&document.getElementById&&!browserinfos.match(/Opera/)
var ns6=document.getElementById&&!document.all
var opera=browserinfos.match(/Opera/)
var browserok=ie5||ns6||opera
function randommaker(range) {
rand=Math.floor(range*Math.random())
return rand
}
function initsnow() {
if (ie5 || opera) {
marginbottom = document.body.clientHeight
marginright = document.body.clientWidth
}
else if (ns6) {
marginbottom = window.innerHeight
marginright = window.innerWidth
}
var snowsizerange=snowmaxsize-snowminsize
for (i=0;i<=snowmax;i++) {
crds[i] = 0;
lftrght[i] = Math.random()*15;
x_mv[i] = 0.03 + Math.random()/10;
snow[i]=document.getElementById("s"+i)
snow[i].style.fontFamily=snowtype[randommaker(snowtype.length)]
snow[i].size=randommaker(snowsizerange)+snowminsize
snow[i].style.fontSize=snow[i].size
snow[i].style.color=snowcolor[randommaker(snowcolor.length)]
snow[i].sink=sinkspeed*snow[i].size/5
if (snowingzone==1) {snow[i].posx=randommaker(marginright-snow[i].size)}
if (snowingzone==2) {snow[i].posx=randommaker(marginright/2-snow[i].size)}
if (snowingzone==3) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/4}
if (snowingzone==4) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/2}
snow[i].posy=randommaker(2*marginbottom-marginbottom-2*snow[i].size)
snow[i].style.left=snow[i].posx
snow[i].style.top=snow[i].posy
}
movesnow()
}
function movesnow() {
for (i=0;i<=snowmax;i++) {
crds[i] += x_mv[i];
snow[i].posy+=snow[i].sink
snow[i].style.left=snow[i].posx+lftrght[i]*Math.sin(crds[i]);
snow[i].style.top=snow[i].posy
if (snow[i].posy>=marginbottom-2*snow[i].size || parseInt(snow[i].style.left)>(marginright-3*lftrght[i])){
if (snowingzone==1) {snow[i].posx=randommaker(marginright-snow[i].size)}
if (snowingzone==2) {snow[i].posx=randommaker(marginright/2-snow[i].size)}
if (snowingzone==3) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/4}
if (snowingzone==4) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/2}
snow[i].posy=0
}
}
var timer=setTimeout("movesnow()",50)
}
for (i=0;i<=snowmax;i++) {
document.write("<span id='s"+i+"' style='position:absolute;top:-"+snowmaxsize+"'>"+snowletter+"</span>")
}
if (browserok) {
window.onload=initsnow
}
looking for some assistance on this js challenge
@lbg232 Do I need a if else?
@Antiaccess Your this might be out of scope
I can't get past the 'no global myVar variable' test
@revisualize yeah same here and my front-end html/css was horrible too :smile:
@jyelton4 your code please
@Joanna15 what is the issue?
@walidashri I just needed to refresh apparently, code was correct
@jyelton4 :) :+1:
Hello campers
Can anybody explain to me why this returns false?
function truthCheck(collection, pre) {
// Is everyone being true?
for (var element in collection) {
if (!collection[element].hasOwnProperty(pre)) {
return false;
}
if (collection[element].pre === undefined) {
return false;
}
}
return true;
}
truthCheck([{"single": "yes"}], "single");
Hello Rich :)
// Setup
var myObj = {
gift: "pony",
pet: "kitten",
bed: "sleigh"
};
function checkObj(checkProp) {
// Your Code Here
myObj.hasOwnPropery(checkProp);
if (true){
return
} else {
return "Not Found";
}
}
// Test your code by modifying these values
checkObj("gift");
am I meant to pass checkProp to hasOwnProperty
Hey everyone, Im working on the algorithm challenge where you push the largest number from a two dimensional array to a new array. My code seems to do that but it repeats each number 3 times. Can someone give me a hint at what I did wrong?
Much Appreciated!
Much Appreciated!
function largestOfFour(arr) {
// You can do this!
var array= [];
for(i = 0; i < arr.length; i ++){
for(j = 0; j < arr[i].length; j ++){
array.push(Math.max.apply(Math,arr[j]));
}
}
return array;
}
largestOfFour([[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39], [1000, 1001, 857, 1]]);
Hi Walid :smile:
@BrennanGlynn cauze all the time this is true
collection[element].pre === undefined)
@walidashri mhhhhh thanks haha
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@Antiaccess It works fine for me
Basically myStr should have encoded text and two correctly escaped backslashes characters. It looks like that now: var myStr = 'First \tLine\n\"second \tLine\"\rThird\tLine';
How do you check for all the values like null undefined NaN etc...?
@BrennanGlynn try stepping through with debugger; then you can see actually happen
no inner quotes or tabs needed... also check correct case on ur words (Second.. with uppercase S ) @Joanna15
@Richie2 do I have to code in a seperate program to do that?
@BrennanGlynn no, you don’t type in debugger; on the line before the for loop, then open up the console log
@BrennanGlynn I will cheack youtube for you
lots to go on there for you.
@domuttel hasOwnProperty() is a method that returns true if the property is found in the object you're searching it. So you should put the whole statement
myObj.hasOwnProperty(checkProp) inside the if statement.
It still doesn't work..
Hi everyone. I want to get some help with an algorithms problem. How do you put code blocks in the chat to show your code? Is it 3 backticks?
@OsakaStarbux Yes 3 tick before code then 3 ticks after
thanks!
@OsakaStarbux 3 backticks before the code, 3 backticks after
'''
:bulb: to format code use backticks! ``` more info
```function palindrome(str) {
// Good luck!
// strip all non alphanumeric chars
var regex = new RegExp('/[^0-9A-Za-z]','g');
str = str.replace(regex,'');
// downcase
str = str.toLowerCase();
// split into array
var currentStringArray = str.split('');
// join into string
var oldString = currentStringArray.join('');
// reverse and join into string
var reversed = currentStringArray.reverse().join('');
// check if array and reversed array are equal
return oldString == reversed;
}
palindrome("eye"); ```
oops
The backticks have to be on their own lines
sorry
Np
@OsakaStarbux press shift +enter to do a line break after ticks
ha! my next question
No problem @OsakaStarbux . Try again
Does anyone have any advice for me? I posted some code further up the chat
function palindrome(str) {
// Good luck!
// strip all non alphanumeric chars
var regex = new RegExp('/[^0-9A-Za-z]','g');
str = str.replace(regex,'');
// downcase
str = str.toLowerCase();
// split into array
var currentStringArray = str.split('');
// join into string
var oldString = currentStringArray.join('');
// reverse and join into string
var reversed = currentStringArray.reverse().join('');
// check if array and reversed array are equal
return oldString == reversed;
}
palindrome("eye");
I'm trying to create an array of objects, I feel like I'm missing somethign simple here:
[1,2,3].map(n=>{num: n})
I'm guessing my regex might be wrong but..
@lowcities you need only one loop
@djcase001 thanks for replying. I wonder why it would work for you and not me
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[1,2,3].map(n=>{num: n}) this returns an array of undefined
@walidashri Ahh OK, I'll try that, Thanks!
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@djcase001 it also doesn't work in another browser for me
@djcase001 clicks between light green, transparent and the normal green
on the down press of the mouse it's supposed to go light green, lift-off the mouse and it goes back to green
@Antiaccess it probably worked for you but it happened so fast
I tried it on my own
@djcase001 no, it stays solid light-green
OK I'm gonna check your codepen to see what the problem is
im working on where art thou and i got stuck here
function whatIsInAName(collection, source) {
// What's in a name?
var arr = [];
// Only change code below this line
var hold = (Object.keys(source));// this is creates array of the property names from source
console.log(hold);
console.log(source[hold]);//this can show the values of the object propertys
for (i=0;i<collection.length;i++) {
console.log(collection[i][hold]);//logs value of
if ( collection[i].hasOwnProperty(hold) && collection[i][hold]==source[hold]){
arr.push(collection[i]);
} else {
console.log(false);
}
}
// Only change code above this line
return arr;
}
whatIsInAName([{ "a": 1, "b": 2 }, { "a": 1 }, { "a": 1, "b": 2, "c": 2 }], { "a": 1, "b": 2 });
@lowcities yea you can just use 1 loop to loop through all 4 sub arrays and return the largest number from each sub array as you did using
Math.max.apply()
@djcase001 thanks
:warning: antiaccess already gave djcase001 points
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ive read about a for in while loop, is that something i need to use
Send me your codepen
Adress
me?
@MoNag1 Yup, that does it, Thanks!
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@wordyallen
[1,2,3].map(n=>{return{'num': n}})
thanks @coffeebeanzz
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thanks @lowcities
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@BrennanGlynn After you run the code with debugger; the program will stop and you can step trough the code. This link gives the commands you can use to step through. https://developers.google.com/web/tools/chrome-devtools/javascript/step-code
@walidashri did you see my code
var myStr ="\FirstLine\n\SecondLine\rThirdLine\";
145 target... myStr looks like above but unfortunately i still don't have any idea how to encoded this text..
145 target... myStr looks like above but unfortunately i still don't have any idea how to encoded this text..
please help
whats the challenge name @Joanna15? the number is just your brownie points the challenges aren't numbered
@joehesse you have spacing issues
there should only be one space between the end of the first sentence and beginning of the second,
you have 3 spaces between the sentences, it needs to be exactly one
like a sentence would be in English
Escape sequences in strings
@djcase001
```
```
@Joanna15 Follow the test with the escape sequences: “FirstLine newline backslash SecondLine backslash carriage-return ThirdLine”
So look at the table and correlate each code with the output
@djcase001
// Setup
var myObj = {
gift: "pony",
pet: "kitten",
bed: "sleigh"
};
function checkObj(checkProp) {
// Your Code Here
if (myObj.hasOwnProperty(checkProp) === true){
return myObj[checkProp][];
} else {
return "Not Found";
}
}
// Test your code by modifying these values
checkObj("guf");
Is this syntax correct?
@Joanna15 yeah what @jrr5230 said
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@joehesse remove the space at the end of the last sentence and I think it'll be ok
Im struggling with how to show the value in an objects list of name value pairs
@awb715 you need to loop through hold items it's an array
The point is that everything is correct but text is still coded
@domuttel your return statement if you find the property doesn't look right
@domuttel if .hasOwnProperty finds the property it should already set it to true. So no need for the (=== true condition).
@Joanna15 no theres some problems with your string
function checkObj(checkProp) {
// Your Code Here
if (myObj.hasOwnProperty(checkProp) === true){
return myObj[checkProp];
} else {
return "Not Found";
}
}
for example you don't need backslashes at the beginning or end of the sentence
FirstLine
newlinebackslashSecondLinebackslashcarriage-returnThirdLine
Hello,
I've found bug in Chunky Monkey course.
take that line and replace the words like newline with its code in the table above
I've got it thank you..
The result is correct, but i can't pass the course.
nothing more or less
Anyone skilled with node.js in here?
ok
@Joanna15 to encode your text use three backticks (```) (Then press Shift + Enter) (Copy and Paste your code)(Then end with three backticks again)
Hello, can someone help me with this:
var hi = ‘hello!’;
document.addEventListener(‘input’, function() {
debugger; // why I don’t have access to hi here?
console.log(hi); // but this works fine?
});
@domuttel looks better but like @jrr5230 said you don't need the === operator, hasOwnProperty returns a true/false value
@domuttel were you able to pass that lesson with your code?
let boo = [];
function chunkArrayInGroups(arr, size) {
// Break it up.
if (arr.length === 0) {
return boo;
}
else if (arr.length < size) {
boo.push(arr.slice(0,size));
return boo;
}
boo.push(arr.slice(0,size));
return chunkArrayInGroups(arr.splice(size),size);
}
The code is as above.
and the result is ok
but i always get x signals in all instructions.
@AndreiLuca99 you can't have global variables in the challenges unless they explicitly give them to you
it messes up the tests and also its generally bad practice to have them
you don't need recursion to solve this problem
Then how can i solve this problem?
I just need to use global variables
you dont need global variables to solve this
if not, it's complicated to finish this one.
try using a for loop instead of recursion to iterate through the array
@chhuang are you sure of this quotes?
‘input’ ‘hello!’;
@kodaxx I'm not, but a lot of the folks here https://gitter.im/nodejs/node are
@walidashri yep
How bad is this?
function findLongestWord(str) {
var strArray = str.split(' ');
var longest = strArray.reduce(function(accu, curr){
if(curr.length >= accu.length){
return curr;
} else{
return accu;
}
});
return longest.length;
}
looks ok to me at first glance @DestroyingLight, is there a problem with it
it works, but in terms of style, can it be done better?
may want to consider using the variable prev instead of accu as that is the nomenclature
also you could use a ternary operator to compact the if/else statement
another thing is you can do this without creating either variable strArray or longest
and lastly you can use ES6 arrow functions
curr.length >= accu.length ? curr : accu
like that?
think you need the return statement still
but you can put it at the beginning once
I think my last message could not be sent
how can i use ES6 syntax on the FCC parser ?
i think it just works
it shows me warnings
I'm having a hard time understanding the mechanics of ===-1 and what it is doing.Can anyone eli5 this for me? Sorry and thanks!
function destroyer(arr) {
var args = Array.prototype.slice.call(arguments);
args.splice(0, 1);
return arr.filter(function(element) {
return args.indexOf(element) === -1;
});
}
destroyer([1, 2, 3, 1, 2, 3], 2, 3);
warnings aren't a big deal
can you see it there?
im not sure how to clear that because i didn't use any es6 first time around doing the challenges
@chazztizer indexOf returns -1 when it cannot find element in args
yeah im trying it now
@chhuang it's not valid :)
@chazztizer Since you want to keep elements that don't match the remaining args -1 would mean that.
@walidashri what is not valid?
@sjames1958gm So arr is being returned, but is filtering out the "element" of args?
@chhuang the qoutes it's
" or '
@DestroyingLight add
'jshint esversion:6' as 1st line in ur code
sorry I may have put in the wrong quote, but the problem is not the quote
@chazztizer If the element is not in args indexOf returns -1 and the function returns true which keeps element, if the element is in args then indexOf returns index and the functin returns false and drops the element
@sjames1958gm Maybe i'm just dumb. Thanks though
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@chhuang did u test the input if you try to type in the debugger should be triggered
@sjames1958gm Hello My Mentor, thanks
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@DestroyingLight
return str.split(' ').reduce((accu, curr) => accu > curr.length ? accu : curr.length, 0);
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@walidashri Hello -
@walidashri I'm not getting it to work
@sjames1958gm I was doing something similar now
function findLongestWord(str) {
const longest = str.split(' ').reduce( (accu, curr) => curr.length >= accu.length ? curr : accu);
return longest.length;
}
it seems to pass the challenge
return str.split(" ").sort().shift().length;
@moigithub that sorts a alphabetically
I think
yea.. probably need a callback on sort...
.sort((a,b)=>a.length-b.length)
something I'm stuck between trying to make code pure, brief, with the least variables possible, AND making it readable
sometimes*
@DestroyingLight
/*jshint esversion: 6 */
thanks @walidashri ! no warnings now
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@DestroyingLight
const findLongestWord = str => Math.max(...str.split(' ').map(w => w.length))
Can someone explain Record Collection to me a bit more then they have written?
I take it when given the parameters are passed I have to add information provided to the obj
Am I meant to update the object before I start?
@walidashri https://jsfiddle.net/pe46d6tp/1/ you can try it in there
hey has anyone done smallest common multiple in the intermediate javascript scripting section that can help me out?
@walidashri: Overkill, no? :point_up: November 22, 2016 7:28 PM Single line comment
//. Come and join us at the lazy table. :smile:
@walidashri thanks!
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@cdrainxv shut up
@chhuang
Hi! I was wondering why I couldn't do return checkProp[myObj]; in the function to get the same result
@walidashri so my question is why is the animal variable not defined when you comment the console.log line out?
@domuttel It wants you to write a function that takes some inputs and checks some parameters in the JSON file which will then update the JSON file
@Terryd12345 OK so this will take a bit of work!
@domuttel Yeah the way its written is a bit confusing but basically just use some if/else statements to check the conditions and then put the correct info in if its true
how can i use the function inside an argument??
function findElement(arr, func) {
var num = 4;
return func;
}
findElement([1, 2, 3, 4], function(num){ return num % 2 === 0; });
@DikoFaji by its name
^ assign it to a variable?
:|
to CALL a function add a set of () at the end of its name
@djcase001 in challenge Finders Keepers the function is set in the var func
yes it is assigned in the variable, and i know that to call function is thru its name. i just wonder in this challenge why the function is assigned in var func?
@DikoFaji you gotta use a built-in JS function in this exercise
and i thought that by returning the var func will run the function. but not
How to make a regular expression matching Symbol “:” in JavaScript
@DikoFaji go take a look back at the built-in array methods
@chhuang debugger issue
@djcase001 my question now is why is the function is placed in argument func?
@DikoFaji it is a callback function that executes once you call the main function
Any guidance on counting cards?
var count = 0;
function cc(card) {
// Only change code below this line
count = 0;
var answer = "" ;
switch (card) {
case 2:
case 3:
case 4:
case 5:
case 6:
answer = count++ + " Bet";
break;
case 7:
case 8:
case 9:
answer = count + " Hold";
break;
case 10:
case "J":
case "Q":
case "K":
case "A":
answer = count-- + " Hold";
break;
}
return count;
// Only change code above this line
}
// Add/remove calls to test your function.
// Note: Only the last will display
cc(2); cc(3); cc(7); cc('K'); cc('A');
changed bottom to return answer;
@DikoFaji in this exercise, the callback function has to filter the array and get the number that matches the condition of the call
@wannabecoding count ++ and count -- go in separate lines. The break statement by itself should suffice for the middle three cases
@wannabecoding I'd use an if statement instead
@djcase001 i think im getting it. ok ill try first
@DikoFaji ok bro
@jrr5230 Don't I have the count++ and count-- in separate lines?
@djcase001 I'll try the if statement, might be easier
@wannabecoding definitely much easier
@wannabecoding
```
```
@wannabecoding
if(card >= 2 && card <= 6){
// your logic
}
@wannabecoding nah...it'll be like
count ++;
count--;
Hello! I cannot seem to get the "Stand in line" code correct
I have gone back to the earlier lessons and I am just completely lost on this section
then
answer = count + string
@Krystinet let us see what you have so far or at least what you tried
@walidashri thanks!
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@Krystinet tell me more
@MoNag1 @djcase001 just logged back in after several days and I have not saved my code
Sorry, I know that's not helpful
first time on the chat
@Krystinet Ok. So you'll have to rewrite it . I'll help you
@Krystinet ok, you understand that it's asking you to first push something called item into your array arr, then remove the first element of arr
yes
okay so we can break it down into 2 steps, lets worry about the push part first. Do you know of any method to push an item into an array?
@Krystinet what challenge is it??
so arr.push(item)?
@djcase001 stand in line
basic, intermediate or Advanced
@Krystinet yep, that's the first step done already
???
right
@djcase001 i believe its under basic javascript?
Yes javascript
@Krystinet ok next you need to find a way to remove the first element of an array, do you know any way that could be done?
.pop
@Krystinet close, pop removes last element
what you're looking for is shift
Right!
(sorry I did those sections twice but haven't gone back in about a week!)
dw we all forget, do you know how you can apply .shift()?
variableName.shift()?
@cdomiano Here is the code that you posted:
function slasher(arr, howMany) {
arr.slice(0);
arr= arr.splice(howMany);
return arr
;
}Let's evaluate
function slasher(arr, howMany) {
arr.slice(0); // this does nothing. So, it isn't needed.
arr= arr.splice(howMany);
// assigning a thinger to a thing just to return the thing is pointless.
return arr
;
}So, we can refactor all of that to...
function slasher(arr, howMany) {
return arr.splice(howMany);
}But, that's just my thoughts. I could be wrong.const slasher = (a, h) => a.splice(h);
@MoNag1 @Krystinet you have to use two array methods to solve this problem
grrrrr.
@Krystinet yep, and your variable name is arr, so do that
There.
@djcase001 yea .push() and .shift()
@cdomiano ------^^^^^^ :D
@MoNag1 @djcase001 arr.shift()
arr.push()
so that part I understand
@Krystinet You have it backwards.
Okay
https://gist.github.com/revisualize/ced4a3a6611c6c74bcab34a07eaa4ebf
Parameters are variables that represent the values that get passed into your function from the function call.
https://cs.wellesley.edu/~cs110/lectures/L16/images/function-anatomy.png
Notice how the variables level and score in the function definition addScore are called parameters.
However, when we invoke the function like in:addScore(3, 10) or addScore(6, 20)
the values are called arguments. Here is an important lesson:
You define a function with parameters, you call a function with arguments.
Another example of this:
function hello(fName, uName) {
return "Hello " + fName + " " + uName + ", How is your day?";
}
hello("Joseph", "@revisualize"); // "Hello Joseph @revisualize, How is your day?"
hello("Bella", "@bellaknoti"); // "Hello Bella @bellaknoti, How is your day?"
hello("Andy", "@dirn"); // "Hello Andy @dirn, How is your day?"You can use the fName and uName parameters just like a variable inside of your function.
Other important things to remember:
* A function can have zero parameters. You still have to use the parentheses to define it.
* A function might have no return statements. In this case we say that the function returns undefined.
....
var name = function() { return "Joseph"; }The push() method adds one or more elements to the end of an array and returns the new length of the array.
The pop() method removes the last element from an array and returns that element.
The shift() method removes the first element from an array and returns that element.
The unshift() method adds one or more elements to the beginning of an array and returns the new length of the array.
@Krystinet alright send your code knowing what you know now
@Krystinet first push the item, and then shift the array into item
But, you know.. meh.
Do I have to set arr and item to something?
@Krystinet
@Krystinet No.
@Krystinet They are parameters.
You know.. That big block of text that I just posted. With images ans stuff.
@revisualize loll
sorry guys, im really being dense on this one
function nextInLine(arr, item) {
// Your code here
arr.push();
item.shift();
return item; // Change this line
}
// Test Setup
var testArr = [1,2,3,4,5];
// Display Code
console.log("Before: " + JSON.stringify(testArr));
console.log(nextInLine(testArr, 6)); // Modify this line to test
console.log("After: " + JSON.stringify(testArr));
@Krystinet item isn't an array.
@Krystinet you should shift arr and not item
@Krystinet function nextInLine which has two parameters an array (
arr) and a number (item).
@Krystinet also, you will need a place to store the new array after the first item has been removed
@Krystinet
item = arr.shift()function nextInLine(arr, item) {
// Your code here
arr.shift();
arr.push();
return item; // Change this line
}
// Test Setup
var testArr = [1,2,3,4,5];
// Display Code
console.log("Before: " + JSON.stringify(testArr));
console.log(nextInLine(testArr, 6)); // Modify this line to test
console.log("After: " + JSON.stringify(testArr));
@Krystinet Why did you change the order?
Ahhh
I DONT KNOW
@Krystinet I think you should take the time to understand the whole block of info that @revisualize posted :)
@Krystinet :point_up: November 22, 2016 7:26 PM
@Krystinet
function nextInLine(arr, item) {
// Your code here
item = arr.push();
item = arr.shift();
return item; // Change this line
}
// Test Setup
var testArr = [1,2,3,4,5];
// Display Code
console.log("Before: " + JSON.stringify(testArr));
console.log(nextInLine(testArr, 6)); // Modify this line to test
console.log("After: " + JSON.stringify(testArr));
@Krystinet Why are you overwriting
item?
@Krystinet
function nextInLine(arr, item) {
// Your code here
arr.push();
item = arr.shift();
return item; // Change this line
}
// Test Setup
var testArr = [1,2,3,4,5];
// Display Code
console.log("Before: " + JSON.stringify(testArr));
console.log(nextInLine(testArr, 6)); // Modify this line to test
console.log("After: " + JSON.stringify(testArr));
item is the number that you need to be adding to the end of the array?
@djcase001 Also wrong.
@revisualize that's how i solved it
With this lesson there is Zero need to overwrite item.
@djcase001 Then you never added item to the end of the array.
@revisualize You're maybe the one who's wrong there
Maybe I am.
I did it completely different @djcase001
like @revisualize no need to overwrite
function nextInLine(arr, item) {
// Your code here
arr.push();
arr.shift();
return item; // Change this line
}
// Test Setup
var testArr = [1,2,3,4,5];
// Display Code
console.log("Before: " + JSON.stringify(testArr));
console.log(nextInLine(testArr, 6)); // Modify this line to test
console.log("After: " + JSON.stringify(testArr));
now back to this, since item does not get over written?
@djcase001 Could you critique my code and tell me if I'm wrong?
function nextInLine(arr, item) {
arr.push(item);
return arr.shift();
}
I am pushing item to the end of the array ... because that is what push does.
I am removing the first element from the array because that is what shift does.
@Krystinet you have to push in an item into the array
But, shift also returns the element that was removed.
So... It satisfies the requirements.
@djcase001 Please let me know where my code is wrong. I'd love to hear it.
...
Look, I'm not trying to sit here and be an ass.
There is a reason that this lesson has
// Change this line
looks right to me +1:
You need to change that line.
I played the game Clue once or twice and I got Clue.
The push() method adds one or more elements to the end of an array and returns the new length of the array.
The shift() method removes the first element from an array and returns that element.
function nextInLine(arr, item) {
// Your code here
arr.push(item);
return arr.shift; // Change this line
}
// Your code here
arr.push(item);
return arr.shift; // Change this line
}
var name = function() { return "Joseph"; }
@Krystinet You're missing the ()
@Krystinet You really need to understand that lesson. It is a very important Data Structure.
$%@$%^%^
It's called a Queue.
function nextInLine(arr, item) {
// Your code here
arr.push(item);
var removed = arr.shift();
return removed;
} I just added an extra variable so mine was a little less efficient lol
Thanks guys!
@revisualize
nextInLine([], 1) should return 1
nextInLine([2], 1) should return 2
nextInLine([5,6,7,8,9], 1) should return 5How you gonna return 1, 2 or 5 if you don't overwrite the item argument
@djcase001 Re-read my code.
@revisualize I absolutely want to understand the lesson! Thank you for your help
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@djcase001 The item gets added to the end of the array.
@djcase001 Then the first element gets removed.
@revisualize ok I see it. but mine is good too
If there are no elements in that array.
@djcase001 Your code doesn't complete for me.
:point_up: November 22, 2016 7:39 PM
Does not complete.
Just tested it.
@revisualize it completed for me
@djcase001
I admit yours was clever than mine, but mine works too
Can someone please help me with my Javascriptpage? can not get it submitted
@djcase001 That's the code that you posted and the test cases.
Thank you @djcase001 @revisualize
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@revisualize you didn't push item in the array first
@djcase001 I copied and pasted the code that you put into chat.
I didn't edit it.
CTRL+C ... CTRL+V
There was a mistake in this one
@Krystinet Do you understand what is going on?
@Krystinet Are you ok now??
@revisualize I think so
@djcase001 I think I get it now
@Krystinet good
I'm going to do some more reading so that it sinks in
@Krystinet I have a link.
@Krystinet go ahead
Actually open that page.. There are two hint links and there are two non-code comments as well.
@revisualize I was able to pass the lesson, but need more practice, for sure!
@FrankSD What page???
@revisualize read through the page, I think it was the syntax of the array mixed with the syntax of the function that threw me. Definitely have a better understanding now, still need more practice of course!
Hey guys!
Anyone want to take a super easy question? Lol
@ParadiseArtist sounds like it'll be a trick question -_-
lol jk
go for it
@jrr5230 Ha I wish I was that smart. I'm not quite getting ...
Wait you guys were working on this above. Yeay! I'm not along.
alone
haha there you go
Let me read over the above code cause I'm stuck on the exact same question.
:+1:
la la la
@ParadiseArtist Just read that link that I posted.
Instructions
Declare a local variable myVar inside myLocalScope. Run the tests and then follow the instructions commented out in the editor.
Hint
Refreshing the page may help if you get stuck.
No global myVar variable
code-
unction myLocalScope() {
var myVar = "use strict";
console.log(myVar);
}
myLocalScope();
// Run and check the console
// myVar is not defined outside of myLocalScope
console.log(myVar);
// Now remove the console log line to pass the test
problem solved
$(document).ready(function() {
var la=30;
var lo=55;
var api='api.openweathermap.org/data/2.5/weather?lat=la&lon=lo&APPID=da3ecbc1d1d3735a28ee453521d25614'
$.getJSON(api,function(response){
console.log(response);
});
});
var la=30;
var lo=55;
var api='api.openweathermap.org/data/2.5/weather?lat=la&lon=lo&APPID=da3ecbc1d1d3735a28ee453521d25614'
$.getJSON(api,function(response){
console.log(response);
});
});
i am not getting response pls anyone help
@Ankitnau25 you need to concat the api string so that it includes the variables la and lo
k @MoNag1
var api="api.openweathermap.org/data/2.5/weather?lat=" + la + "&lon=" + lo + "&APPID=da3ecbc1d1d3735a28ee453521d25614"
Can anyone tell me why 'mouseup' 'mousedown' doesn't change the colour on the down and up mouse click of a div, instead it stays on one color, with this code:
$("#g").on("mousedown", function() {
$("#g").toggleClass('fullGreen');
}).on("mouseup", function() {
$("#g").toggleClass('n-green');
});
link to codepen: https://codepen.io/antiaccess/pen/wogRwp
@Antiaccess Still got that problem
@djcase001 just went out with a mate, got home
@djcase001 so basically starting where I left off
@Antiaccess ok, I'd use the click event instead of mousedown and up
like g.onclick = function()
?
Yeah
@Antiaccess sent you a link in private
@Terryd12345 you still here?
I got Record Collection factored but Im having trouble with it a bit?
function updateRecords(id, prop, value) {
var newArray = [];
if ( prop === "artist" && value !== "") {
collection[id].artist = value;
}
else if ( prop === "tracks" && value !== "" ){
collection[id].tracks = newArray;
collection[id].tracks[0] = value;
}
return collection;
}
@MoNag1
$(document).ready(function() {
var la;
var lo;
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(function(position) {
la=position.coords.latitude;
lo=position.coords.longitude;
});
}
var api="api.openweathermap.org/data/2.5/weather?lat=" + la + "&lon=" + lo + "&APPID=da3ecbc1d1d3735a28ee453521d25614"
$.getJSON(api,function(response){
console.log(response);
});
});
still not getting response @MoNag1
var la;
var lo;
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(function(position) {
la=position.coords.latitude;
lo=position.coords.longitude;
});
}
var api="api.openweathermap.org/data/2.5/weather?lat=" + la + "&lon=" + lo + "&APPID=da3ecbc1d1d3735a28ee453521d25614"
$.getJSON(api,function(response){
console.log(response);
});
});
still not getting response @MoNag1
@Terryd12345 Its passing the tests but not the quiz...
OR if anyone can help me with Record Collection
@Ankitnau25 try adding "http://" to the link
function wordBlanks(myNoun, myAdjective, myVerb, myAdverb) {
var result = "";
// Your code below this line
myNoun=wordBlanks[0];
myAdjective=wordBlanks[1];
myVerb=wordBlanks[2];
myAdverb=wordBlanks[3];
result="My "+myNoun+" is "+myAdjective+" and "+myVerb+" so "+myAdverb;
// Your code above this line
return result;
}
// Change the words here to test your function
wordBlanks("dog", "big", "ran", "quickly");
// Setup
var collection = {
"2548": {
"album": "Slippery When Wet",
"artist": "Bon Jovi",
"tracks": [
"Let It Rock",
"You Give Love a Bad Name"
]
},
"2468": {
"album": "1999",
"artist": "Prince",
"tracks": [
"1999",
"Little Red Corvette"
]
},
"1245": {
"artist": "Robert Palmer",
"tracks": [ ]
},
"5439": {
"album": "ABBA Gold"
}
};
// Keep a copy of the collection for tests
var collectionCopy = JSON.parse(JSON.stringify(collection));
// Only change code below this line
function updateRecords(id, prop, value) {
var newArray = [];
if ( prop === "artist" && value !== "") {
collection[id].artist = value;
}
else if ( prop === "tracks" && value !== "" ){
collection[id].tracks = newArray;
collection[id].tracks[0] = value;
}
return collection;
}
// Alter values below to test your code
updateRecords(5439, "artist", "ABBA");
updateRecords(2548, "artist", "");
updateRecords(5439, "tracks", "Take a Chance on Me");
updateRecords(2548, "tracks", "");
updateRecords(1245, "tracks", "Addicted to Love");
@Antiaccess your green button already has the
n-green class, so just toggle the fullGreen class on both mousedown and mouseup
@leozhon
myNoun myAdjective myVery and myAdverb are parameters for the function. While dog big ran and quickly are arguments to the wordBlanks function. You use the parameters as placeholders. So if you were to simply print out myNoun the parameter, it would print out "dog" in this instance. You don't access them via an array of the function.
ok
got it @MoNag1 but la and lo are not returning
@Ankitnau25 I believe you can no longer access geolocation like that, you need to get coordinates through ip-api.com. You can check out a video that explains it here
@toianw legend! seems counterintuitive, but it works
@toianw thanks
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@domuttel - y ou should not have to use a special check for "artist" - the main thing that distinguishes actions based on the property names is either the property is "tracks" or it isn't. And you do not have the condition covered where the
value === "" where you should delete a property.
@toianw actually, it kind of makes sense
@leozhon I don't think that is what the challenge is expecting you to do, you are over thinking it
thanks a lot @MoNag1 can u suggest me resource for ajax calls i am getting difficulty in them
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@Antiaccess it's just adding the class on mousedown and removing the class on mouseup.
@domuttel The instructions never mention artist.
@domuttel Why are you overwriting tracks array's that already have data?
@leozhon - you are doing something that is not going to work with your access of
wordBlanks[0], etc - wordBlanks is the function name, you can directly access the variables (which are the function parameters) myNoun, myAdjective, etc. in the code without the actions that you are taking to try and assign values to them. Their values are assigned by the function call.
@toianw yeah, I think was to close to the issue that I didn't see it
@leozhon
wordBlanks is not an array.. It is a function
@revisualize @khaduch I am on the right track with tracks then... Im off on artists
@Ankitnau25 I struggle with them too, I just learnt off viewing other people's code and seeing how they did it, not sure if that's the best way tho. Codeacademy has a course called "how to use API's with Javascript" but it's very basic
@domuttel No. You're overwriting tracks that already have data. You shouldn't be doing that.
@Antiaccess did you see the link???
@djcase001 nope
@djcase001 in this chat?
@djcase001 ok
@djcase001 got it
thanks for help @MoNag1
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@Antiaccess 👍🏽
@domuttel - "artists" is definitely not necessary to handle as a special case. That being said, you could certainly make it one, but then you would also have to do that for all of the possible properties (and some of them you would potentially not know, unless you had the complete list of possible function calls that gave them to you.) So you have to have two cases -
prop === "tracks" and the opposite of that - an if and an else. Also you have to be careful how you handle the tracks property and value associated with it - it is an array or should be one. If you already have an array there, you just want to add to it. Other times you don't have the array and you need to create it.
So I am essentially deleting the arrays before I do anything?
is this a case for hasOwnProperty?
@domuttel - Bingo!
.hasOwnProperty() is just the ticket!
( prop === collection[id].hasOwnProperty("tracks") )
@domuttel
.hasOwnPropery() returns either true or false.
.hasOwnProperty is referring to artists in this case @khaduch
Hello all, please my code is giving errors. Am writing algorithm scripting - find the longest word in a string
Here's my code:
function findLongestWord(str) {
var words = str.split(' ');
var maxLength = 0;
for(var i = 0; i < words.length; i++) {
if(words[i].length > maxLength) {
maxLength = words[i].lenght;
}
}
return maxLength;
}
findLongestWord("The quick brown fox jumped over the lazy dog");
@kingisaac95
maxLength = words[i].lenght; check length spelling on that line
@khaduch ( collection[id].hasOwnProperty("tracks") === true )
is there anything wrong with my code function caseInSwitch(val) {
var answer = "";
// Only change code below this line
switch (val){
case "1":
console.log("alpha");
break;
case "2":
console.log("beta");
break;
case "3":
console.log("gamma");
break;
case "4":
console.log("delta");
break;
}
// Only change code above this line
return answer;
}
// Change this value to test
caseInSwitch(2);
@gandledorf need to return
alpha beta and so on so you have to set answer equal to alpha and so on for it to return answer
Anyone PLEASE help me with the Mad Libs "WORD BLANKS" game......WHAT SHOULD BE THE CODE BETWEEN COMMENTS BLOCK?????\
function wordBlanks(myNoun, myAdjective, myVerb, myAdverb) {
var result = "";
// Your code below this line
// Your code above this line
return result;
}
// Change the words here to test your function
wordBlanks("dog", "big", "ran", "quickly");
@shyrushh think you need to concat a string with those words provided
@heroiczero thanks
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@shyrushh just make a sentence with the
variables provided by the function wordBlanks(myNoun, myAdjective, myVerb, myAdverb) and then set it equal to result
@shyrushh Combine the arguments inside the wordBlanks brackets. Make sure you add a space inbetween each word so that it's a proper sentence
THANK YOU ALL FOR THE QUICK RESPONSE :+1:
@heroiczero Thanks a lot
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if ( collection[id].hasOwnProperty("tracks") === false ){
collection[id].tracks = newArray;
collection[id].tracks.push(value);
}
@khaduch
if (collection[id].hasOwnProperty("tracks") === false){ collection[id].tracks = []; } collection[id].tracks.push(value);
@revisualize thats what I have
@domuttel You have newArray defined elsewhere then you're using it.
You're only going to use newArray once.
Hey guys I have a question regarding the Mutations JavaScript algorithms exercise
I get all the test cases right except ("hello", "hey")
My code is as follows:
@domuttel the condition part in the
if statement automagically checks for truthy value
oh ok that makes way more sense
function mutation(arr) {
valid = true;
for (var i = 0; i < arr[1][0].length; i++) {
if (arr[0].toLowerCase().indexOf(arr1.charAt(i).toLowerCase()) == -1) {
valid = false;
}
return valid;
}
}
mutation(["hello", "hey"]);
@domuttel if
then execute the statements
truthythen execute the statements
@abhisekp but it is set to equal false
@domuttel you can negate it by using
! operator :D
@domuttel e.g.
if ( !truthy )myObj.hasOwnProperty(checkProp) !=if (!myObj.hasOwnProperty(checkProp))
...
oh duh
@revisualize
```
```
@revisualize
if ( !collection[id].hasOwnProperty("tracks") ){
collection[id].tracks = [];
}
collection[id].tracks.push(value);
else {
}
is this the right dirrection?
Im really struggling with this one...
@domuttel What's the else going to be?
Im wondering about adding the aritist name
@karthikm0
```js [shift + enter for newline]
<code here>
``` [ctrl + enter to post]
hello guys! need help.
Modify the function checkObj to test myObj for checkProp. If the property is found, return that property's value. If not, return "Not Found".
my code:
var myObj = {
gift: "pony",
pet: "kitten",
bed: "sleigh"
};
function checkObj(checkProp) {
if (true) {
myObj.hasOwnProperty(checkProp);
return myObj.checkProp;
}
return "Change Me!";
}
checkObj("gift");the function doesn't work, console displays nothing. why?
@erselnordlys Test the hasOwnProperty expression, not
true.
You also need to use the bracket notation then the property key is in a variable like
checkProp.
@Masd925
ok, now this is what the function looks like. console displays "Change me!". what is wrong?
ok, now this is what the function looks like. console displays "Change me!". what is wrong?
function checkObj(checkProp) {
if (myObj.hasOwnProperty[checkProp]) {
return myObj[checkProp];
}
return "Change Me!";
}
@erselnordlys
...hasOwnProperty(...) <- parens here, it is a method.
@Masd925 why exactly bracket notation instead of dot?
@erselnordlys The dot notation only works if the property key string is a valid JS identifier (for example "12" and "lives left" are not) and you write the key after the dot:
var cat={clothes:"pants", "lives left":3}; cat.clothes; //returns "pants". Bracket notation works with keys that can be arbitrary strings cat["lives left"]; //returns 3, variables var key="clothes"; cat[key]; //returns "pants", or expressions cat["lives"+" "+"left"]; //returns 3.
@Masd925 sure, parens! thanks
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Question.. In Russia. If I want AK47 ... Do I just go to middle school and they build me one? Is it one of those situations where I get an AK and they get a good grade?
Boolean("Do I just go to middle school and they build me one? Is it one of those situations where I get an AK and they get a good grade?"); // true
@revisualize lol
@erselnordlys So, bracket notation evaluates the expression inside the brackets into a string and uses it as a key, and dot notation just uses the string written after the dot.
I swear.. It should be like a shop class assignment.
@Masd925 so what is the type of key "checkProp" in this code? and what are valid JS identifiers for example?
@erselnordlys
checkProp is the function parameter (a variable in the function execution context that holds the passed key). The passed key is a string.
@revisualize you americans have a really wrong impression about russians :D
btw. I am not a russian :)
@kirbyedy Actually, I just want a really bad ass Russian built AK-47.
@Masd925 i got it, thanks a lot!
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@erselnordlys that goes into a lot of detail, but this is the important bit
An identifier must start with $, _, or any character in the Unicode categories “Uppercase letter (Lu)”, “Lowercase letter (Ll)”, “Titlecase letter (Lt)”, “Modifier letter (Lm)”, “Other letter (Lo)”, or “Letter number (Nl)”.
@kirbyedy I have a crappy American Made one.
Okay maybe it isn't crappy. But, still .. you get the idea.
@erselnordlys so if you want, you can write all of your variables in arabic or chinese or russian or whatever.
You Americans are fucking stupid... Just like the rest of us really!
@adityaparab Yee haw?
:laughing:
@DanCouper i'm not that deep in JS yet... I dont get it now
Parameters are variables that represent the values that get passed into your function from the function call.
https://cs.wellesley.edu/~cs110/lectures/L16/images/function-anatomy.png
Notice how the variables level and score in the function definition addScore are called parameters.
However, when we invoke the function like in:addScore(3, 10) or addScore(6, 20)
the values are called arguments. Here is an important lesson:
You define a function with parameters, you call a function with arguments.
Another example of this:
function hello(fName, uName) {
return "Hello " + fName + " " + uName + ", How is your day?";
}
hello("Joseph", "@revisualize"); // "Hello Joseph @revisualize, How is your day?"
hello("Bella", "@bellaknoti"); // "Hello Bella @bellaknoti, How is your day?"
hello("Andy", "@dirn"); // "Hello Andy @dirn, How is your day?"You can use the fName and uName parameters just like a variable inside of your function.
Other important things to remember:
* A function can have zero parameters. You still have to use the parentheses to define it.
* A function might have no return statements. In this case we say that the function returns undefined.
just as long as you don’t call your variable “var” or “function” or whatever you’ll be fine
...
@Masd925 Do I need to fix that text?
@Masd925 Do I need to fix that text?
var π = Math.PI;
var ಠ_ಠ = "ahem";
var λ = function() {};
@DanCouper ahem...ahem...
@erselnordlys ----^^^ ...
checkProp is a parameter.
@revisualize lovely graph mate, thanks
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very impressive! very impressive!
vveeeeerryy impressive
Crap.. Look at the time.
Okay it is 1113pm here in Seattle.
I need to jet.
:v:
Same in San Francisco
@revisualize how does it works with zero parameters? What will it return?
@DanCouper well I got it haha! var function is fun
@DanCouper well I got it haha! var function is fun
@erselnordlys You have to code around it.
@erselnordlys Something like this.
var Hͫ̆̒̐ͣ̊̄ͯ͗͏̵̗̻̰̠̬͝ͅE̴̷̬͎̱̘͇͍̾ͦ͊͒͊̓̓̐_̫̠̱̩̭̤͈̑̎̋ͮͩ̒͑̾͋͘Ç̳͕̯̭̱̲̣̠̜͋̍O̴̦̗̯̹̼ͭ̐ͨ̊̈͘͠M̶̝̠̭̭̤̻͓͑̓̊ͣͤ̎͟͠E̢̞̮̹͍̞̳̣ͣͪ͐̈T̡̯̳̭̜̠͕͌̈́̽̿ͤ̿̅̑Ḧ̱̱̺̰̳̹̘̰́̏ͪ̂̽͂̀͠ = 'Zalgo';
@DanCouper why are the texts crying? :'(
@erselnordlys
var name = function() { return "Joseph"; }What do you think the value of the variable name is?
@DanCouper : THere is name for people who use variables like that... It's called "animals"
@revisualize i spose it will be "Joseph', right?
@erselnordlys You'll find out later about the
arguments key word. And what it allows you to do.
@erselnordlys that's correct.
@erselnordlys : It'll be
[Function name] ;)
@erselnordlys Save that knowledge for later. It will be useful.
T̵͎̠h̤̣̗̙̥͝o̟̮͎̯̕s͉̦̘̠̥e͉̮̥ ̻a͎̖̪̰r̴͈e͇̺͙͢ ̨͖̫̺̤̦̠̱t̗͓̠̞͓̕h̭̗̘̦̦ẹ̳̼͝ ̸̰̖̘͓̪̱̭c̡̳͈̣̖̮h̷͈͍͎ͅo̷̪̘̜se̡̞̝̺̱n̻͎̲̭̱͡, ̮͍̬̜̫̝̀t̡͇̭̯̟̹̣̲ḩ̰͍̯òṣ͎͈͚͚̰̼e͙̞̘̹̻͢ ̛̩͉̣̼͓̥w͈̙̟h̷̥͈̩̺̯͙o̢̫͇͈͉͖ͅͅ ̥̫̝̭͔̤͉u̻̩̰͙̣̖͝s͕̫̩͉e̪̪̥̮͙ ̺̯͡ͅͅt̫̰h̜̙̗̯͎̰͚̕e ̠̤͟V̗͍͙̩̤̹̹A̙̟̜̰̕R̨̲̹Í̩͖̣A͈BL͍̰͚E̷̲̳̪̳S͇̣ ͇̭o̲f͈̺̲ ̴̹Z͔͔͓̩ͅḀ̢̣LG͓̺͚̘̯̭O͚̘
var name is assigned to a function. But that function is not called. So the value of name will be a function.
meh.. Kind of.
:point_up:
How to Set remainder equal to the remainder of 11 divided by 3 using the remainder (%) operator?
remainder = 11 % 3
literally the same as you wrote it
let remainder = 11%3;
Okay. technically yes.
@revisualize @DanCouper well thanks! i'll keep going
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@revisualize Is the AK thing pointed towards me?
@domuttel Technically yes. Technically, it is currently pointed in the direction of everyone on this planet.
Hey! Can anyone check my pen?https://codepen.io/cabello986/pen/rrgdpV?editors=1010
specifically the animate function,if you click ON and try playing along well....the animations arent working correctly
specifically the animate function,if you click ON and try playing along well....the animations arent working correctly
Stupid Earth being an oval and not a sphere.
Have you thought about a UV lamp?
Here...
function getName() { return "Joseph" }
var name = getName();
console.log(name);
@domuttel What? Why?
OKAY!
I must get the :zzz:
:v:
Man take a break dont lash out... We all are just trying to learn. Im not looking for an answer but some guidance. This stuff is hard
Was that directed at me?
:| I don't get it.
I sleep.
:v:
@revisualize I think that the function explanation text is good. If you would like to be more precise, parameters are part of the function declaration and when the function is called, an execution context is formed and there parameters are variables that hold the passed arguments. So just calling them variables is less correct in my opinion.
Go sleep!
@Masd925 Thanks. I will look at seeing if I can correct the text a little.
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@Masd925 :point_up: November 21, 2016 7:11 PM
var myObj = {
gift: "pony",
pet: "kitten",
bed: "sleigh"
};
function checkObj(checkProp) {
if(myObj.hasOwnProperty(checkProp)){
return myObj.checkProp;
}
return "Not Found";
}
checkObj("gift");
gift: "pony",
pet: "kitten",
bed: "sleigh"
};
function checkObj(checkProp) {
if(myObj.hasOwnProperty(checkProp)){
return myObj.checkProp;
}
return "Not Found";
}
checkObj("gift");
someone to help me debug the code above, its printing undefined, what could be wrong?
@Samuel-Mumo your prop is actual string and you can't access an object this way
@Samuel-Mumo it looks like myObj."gift"
However there's always another way to access objects
@abhisekp ok, thanks.
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@kyauhen thanks, i haved used myObj[gift] and it worked
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Hey guys, I've been working on the
simon game and I'm having all of the notes play at the same time despite a time interval. I think I'm using it wrong. Can anyone confirm: for (var i = 0; i < simonArr.length; i++){
setTimeout(output(simonArr[i], 1000));
}
codepen link^
You'll notice all the sounds & color-changes happen simultaneously
making the game unplayable
any awake aussies here?
var phoneticLookup= {
// Only change code below this line
"alpha": "Adams",
"bravo": "Boston",
"charlie":"Chicago",
"delta": "Denver",
"echo": "Easy",
"foxtrot": "Frank"// Only change code above this line
};
// Change this value to test
phoneticLookup("charlie");
whats problem?
hello, I have a problem sorting an array with numbers.
phoneticLookup("") should be undefined
cannot use case, switch, or if
commaArraySort =commaArray.sort(function (a, b) { return a - b; });
this should sort the numbers from low to high, right?
yep
but it doesn't
if I return commaArraySort it still gives the array as before
it works
the typeError is phoneticLookup is not a function
correctly
var commaArraySort = [1,453,2,3,55,1];
commaArraySort =commaArraySort.sort(function (a, b) { return a - b; }); // [ 1, 1, 2, 3, 55, 453 ]
but i didnot use function ,right?
@lawfets Sort is a mutator method, so
commaArraySort.sort... is enough.
how come it doesn't work with me???
@lawfets Post the whole code.
@Masd925 yes but I want to know why it doesn't work my way and it works for others
@Masd925
[1,453,2,3,55,1].sort(function (a, b) { return a - b; }); is enough
@dagman Yes, I said that already.
@lawfets
[1,453,2,3,55,1].sort(function (a, b) { return a - b; }); is enough
@Masd925 sorry i see
@lawfets
@dagman @Masd925 @liuyueweilan thx for the help, the fault is not in that line, just found out what is wrong
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Hi to all! :smile:
I had to use the string.split to change string into array instead of putting string into array
What is the simplest way to deal with this in JavaScript? Anyone knows?
input array = [ [ 1, 'Hair Pin' ],
[ 2, 'Hair Pin' ],
[ 21, 'Bowling Ball' ],
[ 67, 'Bowling Ball' ] ]
result = [ [ 3, 'Hair Pin' ],
[ 88, 'Bowling Ball' ],
]
@elminsterrr nested for loops for the 2d input array and use another array to put your results in while your looping though the input looking for matching conditions. this can be done with
filteras well.
HI guys
filter would be simplest way.
Why does parseInt(021, 8); return 15?
instead of 17
@rledford I tried something like this:
arraysOfDuplicate.filter(function(arrayofDupEl) {
arraysOfDuplicate.filter(function(arrayofDupOneMoreTime) {
if (arrayofDupEl[1] === arrayofDupOneMoreTime[1]) {
sum += arrayofDupOneMoreTime[0];
}
});
console.log('...', arrayofDupEl);
});
console.log(sum);But my output is: 182 :(
[ [ 1, 'Hair Pin' ],
[ 2, 'Hair Pin' ],
[ 21, 'Bowling Ball' ],
[ 67, 'Bowling Ball' ] ]
... [ 1, 'Hair Pin' ]
... [ 2, 'Hair Pin' ]
... [ 21, 'Bowling Ball' ]
... [ 67, 'Bowling Ball' ]
182
I wish
Array#sort were not a mutator method.
@rledford My logic is broken here
is there a way to contain the notation in a variable? i know this one don't work
var arr1 = [1,2,[1,[3]]];
link = arr1[2][1];
return link[0]; //would like to return 3
@liuyueweilan use phoneticLookup["charlie"];
So I've been running into some Codepen issues in the intermediate front end challenges, and have since read that these are common headaches that well may be eliminated with the curriculum update that requires totally different projects for certification... Is it worth battling through the current projects? I've kind of hit a motivational wall here, any input would be appreciated. :)
@elminsterrr
array.filter(function(arr){ if (arr[0] === someValue) reurn newArr;}); it will be something like that your are trying to get the result you specified above. also where newArr is a local variable inside the filter function defined. sry for my formatting. on mobile.
not return... appened to newArr and return after all items have been looked at sry.
I need some help with the "Stand in Line" challenge, one of the javascript exercises
I have a function with an array and a number as arguments, I have to add the number to the end of the array, then remove the first element of the array and return said element
I used .push to add the number, then I tried with .shift to remove the first element, but idk how to return it
Shift returns the element removed.
So, just return the shift.
Oh, I see
I thought that would return the array without the 1st element
Thanks, @revisualize
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\
Hi please help me : how is the first function a , different with the second function a. here's my code http://codepen.io/alienmon/pen/mOmpBR?editors=1010
```function a() {
$.ajax({
url: "https://en.wikipedia.org/w/api.php?action=query&list=search&srsearch=Albert%20Einstein&origin=*&format=json&utf8=",
dataType: 'json',
type: 'POST',
headers: {
'Api-User-Agent': 'josephine monica'
},
}).done(function(data) {
$("#data").html(JSON.stringify(data));
})
};```
function a() {
$.ajax({
url: "https://en.wikipedia.org/w/api.php?action=query&list=search&srsearch=Albert%20Einstein&origin=*&format=json&utf8=",
dataType: 'json',
type: 'POST',
headers: {
'Api-User-Agent': 'josephine monica'
},
}).done(function(data) {
$("#data").html(JSON.stringify(data));
})
};function a() {
$.ajax({
url: "https://en.wikipedia.org/w/api.php?origin=*",
dataType: 'json',
type: 'POST',
headers: {
'Api-User-Agent': 'josephine monica'
},
context: {
"action": "query",
"list": "search",
"srsearch": "Albert Einstein",
// "origin":"*",
"format": "json",
"utf8": ""
}
}).done(function(data) {
$("#data").html(JSON.stringify(data));
})
};
How's the two dunctions above different?
The first function work, while the second function doesn't..
In the second function I put things inside the context, while in the first function put it after the question mark url
please advise
Actually both functions give no error in console... but the first function prints the JSON respones to the #data
BUT the second doesn't print
please help me :)
@elminsterrr Reduce is the correct method here. For example like this:
var array = [ [ 1, 'Hair Pin' ],
[ 2, 'Hair Pin' ],
[ 21, 'Bowling Ball' ],
[ 67, 'Bowling Ball' ] ];
array.reduce(function(acc,curr,index){
if (index>0 && curr[1]===acc[acc.length-1][1]) acc[acc.length-1][0]+=curr[0];
else acc.push(curr);
return acc;
},[]); // [ [ 3, 'Hair Pin' ], [ 88, 'Bowling Ball' ] ]@rledford ok, so far I have samoething like this, better then before :smile:
var newArrHP = [];
var newArrBB = [];
var array = [
[ 1, 'Hair Pin' ],
[ 2, 'Hair Pin' ],
[ 21, 'Bowling Ball' ],
[ 67, 'Bowling Ball' ]
];
array.filter(function(arr) {
console.log(arr[0]);
console.log(arr[1]);
if (arr[1] === 'Hair Pin') {
newArrHP.push(arr[0]);
}
if (arr[1] === 'Bowling Ball') {
newArrBB.push(arr[0]);
}
return 99999;
});
console.log('newArrHP', newArrHP);
console.log('newArrBB', newArrBB);OUTPUT:
1
Hair Pin
2
Hair Pin
21
Bowling Ball
67
Bowling Ball
newArrHP [ 1, 2 ]
newArrBB [ 21, 67 ]
@Masd925 wow, nice one!
@elminsterrr You are not removing elements from array, so filter doesn't work here.
@Masd925 what is the role of "index" in your code?
@elminsterrr It is the index of the array element being iterated by reduce.
When we are at the first index, it is sure that there is no such item there in the result array.
Hello. I am currently stuck on this: https://www.freecodecamp.com/challenges/concatenating-strings-with-the-plus-equals-operator#?solution=%0A%2F%2F%20Example%0Avar%20ourStr%20%3D%20%22I%20come%20first.%20%22%3B%0AourStr%20%2B%3D%20%22I%20come%20second.%22%3B%0A%0A%2F%2F%20Only%20change%20code%20below%20this%20line%0A%0Avar%20myStr%20%3D%20%22This%20is%20the%20first%20sentance.%20%22%3B%0AmyStr%20%2B%3D%20%22This%20is%20the%20second%20sentance.%22%3B%0A%0A%0A what am I doing wrong?
@Masd925 ok, very nice and short solution
but I dpn't understand this -> [acc.length-1]
but I dpn't understand this -> [acc.length-1]
@elminsterrr
arr[arr.length-1] is always the last element of an array arr.
@esgameco I think the only mistake you made is the typo in word
sentence. You got a instead of e
@xeho91 Oh, thanks
esgameco sends brownie points to @xeho91 :sparkles: :thumbsup: :sparkles:
:cookie: 307 | @xeho91 |http://www.freecodecamp.com/xeho91
@elminsterrr So if the item being iterated has the same name as the last item in the accumulator, we add the number to the quantity of the last item in the accumulator.
hey guys I'm stuck :( it's "Falsy Bouncer" challenge and here's my code
function bouncer(arr) {
// Don't show a false ID to this bouncer.
var boolean = "";
for (var i = 0; i < arr.length; i++) {
boolean = Boolean(arr[i]);
if (arr[i] !== false && arr[i] !== null && arr[i] !== 0 && arr[i] !== "" && arr[i] !== undefined && !isNaN(arr[i])) {
return boolean;
}
}
}
bouncer([7, "ate", "", false, 9]);
@Skidle
isNaN is not a test for value NaN.
isNaN("cat"); // true
@Masd925 oh thanks
skidle sends brownie points to @masd925 :sparkles: :thumbsup: :sparkles:
:star2: 2985 | @masd925 |http://www.freecodecamp.com/masd925
@Masd925 so I write it as
arr[i] !== NaN ?
@Skidle That won't work because NaN is not equal to any value.
Even
NaN===NaN is false.
@Masd925 that's crazy :smile:
weird
@Skidle A test for value not being NaN is
val===val
that's the key!
@Masd925 thank you!
skidle sends brownie points to @masd925 :sparkles: :thumbsup: :sparkles:
:warning: skidle already gave masd925 points
developers had to test for
NaN so much so that they invented Number.isNaN method
Number.isNaN = function isNaN(value) {
return value !== value;
}
developers are crazy!!!!
I don't understand how to use
array.filter(); I already checked out the documentation and some exampes but I still don't get it
do I need to put a function inside those brackets?
@Skidle You pass a callback function there that tells filter which elements to keep. Filter passes each array element into the callback function and keeps those that return true.
@Masd925 ok so I need a function (I guess
Boolean();) which returns true or false ?
@Skidle You need to pass a function, so you would pass
Boolean, not Boolean() which would be the return value when you call it without arguments.
@Masd925 I thought that the function always has brackets... :worried: thanks I'll try to do it now!
skidle sends brownie points to @masd925 :sparkles: :thumbsup: :sparkles:
:warning: skidle already gave masd925 points
How can I increment or decrement a global variable from inside a function?
var count = 0;
function cc(card) {
// Only change code below this line
var count = 0;
switch (card){
case 2:
case 3:
case 4:
case 5:
case 6:
count++;
break;
case 7:
case 8:
case 9:
break;
case 10:
case 'A':
case 'J':
case 'K':
case 'Q':
count--;
break;
}
if(count > 0){
return "Bet";
}
else if (count <= 0){
return "Hold";
}
return "Change Me";
// Only change code above this line
}
// Add/remove calls to test your function.
// Note: Only the last will display
cc(2); cc(3); cc(7); cc('K'); cc('A');
This is what I've written and it doesn't seemed to work. Please help :0
@DevD01 By just incrementing it.
count++ for example.
im converting celsius to fahrenheit. and dont understand what im doing wrong.
@Masd925 I don't get it sorry
You need to return
count + " Bet" etc.
@jkilgore07 where are you stuck
@Masd925 I've defined a local variable count inside the function, have I done that right?
@DevD01 No, you should just use the global variable.
@Masd925 okay, then how am I suppose to alter a global variable from inside the function, you are getting it
@DevD01 You can use global variables inside functions.
@DevD01 if you declare a function inside the function then it turns to 0 every time the function is called, just use the global variable, a global variable is accessible everywhere, even inside functions
I tried that but it's not working
Problem is the return values.
@DevD01 global means you don't have to declare it (ie 'var = count' ) again.
@Mozar10 The algorithm to convert from Celsius to Fahrenheit is the temperature in Celsius times 9/5, plus 32.
You are given a variable celsius representing a temperature in Celsius. Use the variable fahrenheit already defined and apply the algorithm to assign it the corresponding temperature in Fahrenheit.
@jkilgore07 so where are you getting stuck?
@DevD01 Return
count + " Bet" etc.
@Masd925 if I'm using return then I'm getting an error: unreachable break after return
im not sure how to build the equation. the number for celsuis x9/5+32?
when i try that it works for a few then it gives me errors
paste your code
function convertToF(celsius) {
var fahrenheit;
// Only change code below this line
fahrenheit=30*1.8+32;
// Only change code above this line
return fahrenheit;
}
// Change the inputs below to test your code
convertToF(30);
@jkilgore07 Use parameter
celsius, not fixed value 30
@jkilgore07 celsius * (9/5) + 32
@jkilgore07 When you call convertToF with argument 30, the first parameter (
celsius) will receive the value 30 for that function call.
Okay Guys here's my Code:
var count = 0;
function cc(card) {
switch (card){
case 2:
case 3:
case 4:
case 5:
case 6:
return count++ + "Bet";
case 7:
case 8:
case 9:
return count;
case 10:
case 'A':
case 'J':
case 'K':
case 'Q':
return count-- + "Hold";
}
if(count > 0){
return "Bet";
}
else if (count <= 0){
return "Hold";
}
return "Change Me";
var count = 0;
function cc(card) {
switch (card){
case 2:
case 3:
case 4:
case 5:
case 6:
return count++ + "Bet";
case 7:
case 8:
case 9:
return count;
case 10:
case 'A':
case 'J':
case 'K':
case 'Q':
return count-- + "Hold";
}
if(count > 0){
return "Bet";
}
else if (count <= 0){
return "Hold";
}
return "Change Me";
@jkilgore07 having (celsius) in the brackets like that is the same as if you said var = celsius, inside your function. It's just a variable inside the function
@DevD01 Don't return inside the switch. Just increment or decrement, or do nothing. Don't forget to break.
@DevD01 You should however return
count + " Bet" (note that extra space, as there should be one between the number and the word) in your if-else (which does not need a second if).
@DevD01 and you should delete return "Change Me" eventhough you won't ever reach it
@Mozar10 @Blauelf :
var count = 0;
function cc(card) {
switch (card){
case 2:
case 3:
case 4:
case 5:
case 6:
count++;
break;
case 7:
case 8:
case 9:
break;
case 10:
case 'A':
case 'J':
case 'K':
case 'Q':
count--;
break;
}
if(count > 0){
return count +"Bet";
}
else
return count+"Hold";
}
cc(2); cc(3); cc(7); cc('K'); cc('A');
var count = 0;
function cc(card) {
switch (card){
case 2:
case 3:
case 4:
case 5:
case 6:
count++;
break;
case 7:
case 8:
case 9:
break;
case 10:
case 'A':
case 'J':
case 'K':
case 'Q':
count--;
break;
}
if(count > 0){
return count +"Bet";
}
else
return count+"Hold";
}
cc(2); cc(3); cc(7); cc('K'); cc('A');
return count + " Bet";
and return count + " Hold";
@DevD01 Remember what I said about the space?
@DevD01 You should however return
count + " Bet"(note that extra space, as there should be one between the number and the word) in your if-else (which does not need a second if).
@Blauelf @Mozar10 right on it, checking that!
@Blauelf @Mozar10 Yayyyyyyy!!
it worked!!
it worked!!
Thanks guys!!
:+1:
:thumbsup:
@Blauelf @Mozar10 hmmmm. maybe im getting caught up onn the wrong thing, but i am confused as to how the equation knows to pull the correct input numbers to plug in where (celsius) is?
when you call the function at the end you are giving it a number right? that is the Celsius value
@jkilgore07 When you call convertToF with
convertToF(30), its first parameter will receive the value 30. That parameter is named celsius, and behaves about like a pre-initialized variable, initialized to that value 30. Name is arbitrary, but that's how you can access the argument passed to your function.function greet(name) {
console.log("Hello, " + name);
}
greet("Blauelf"); // prints Hello, Blauelf
@jkilgore07 Whatever number you use as the argument i.e. inside the brackets when you call the function, is the value of Celsius, That's how the function knows....
convertToF(50) means Celsius is 50, convertToF(20) means Celsius is 20 and so on...
convertToF(0) should return a number
convertToF(-30) should return a value of -22
convertToF(-10) should return a value of 14
convertToF(0) should return a value of 32
convertToF(20) should return a value of 68
convertToF(30) should return a value of 86
convertToF(-30) should return a value of -22
convertToF(-10) should return a value of 14
convertToF(0) should return a value of 32
convertToF(20) should return a value of 68
convertToF(30) should return a value of 86
@jkilgore07 In my example, I pass "Blauelf" as the first argument. That value is then assigned to the parameter variable
name in my function, which I can use to access the string.
these are the checks for the test
I'm on a "Falsy Bouncer" challenge now and this code works for everything but that particular
arr How can I fix this, please?
function bouncer(arr) {
// Don't show a false ID to this bouncer.
var newArr = [];
for (var i = 0; i < arr.length; i++) {
Boolean(arr[i]);
if (Boolean(arr[i]) === false) {
newArr = arr.filter(Boolean);
} else
newArr = arr;
}
return newArr;
}
bouncer([7, "ate", "", false, 9]);i only put in 30 at the bottom to define celsius so why is solving all the others as well?
function convertToF(celsius) {
var fahrenheit;
// Only change code below this line
fahrenheit=celsius*1.8+32;
// Only change code above this line
return fahrenheit;
}
// Change the inputs below to test your code
convertToF(30);
@jkilgore07 The test cases are to ensure that your solution is written correctly, and not specifically for one scenario
°C x 9/5 + 32
@jkilgore07 use 9/5
@Mozar10 ok lol. i was so confused on how it was getting the other answers when i didnt input them. I thought i was completely lost.thanks
:thumbsup:
@Blauelf thank you as well. Makes perfect sense now
jkilgore07 sends brownie points to @blauelf :sparkles: :thumbsup: :sparkles:
:star2: 2987 | @blauelf |http://www.freecodecamp.com/blauelf
I'm on a "Falsy Bouncer" challenge now and this code works for everything but that particular arr How can I fix this, please?
function bouncer(arr) {
// Don't show a false ID to this bouncer.
var newArr = [];
for (var i = 0; i < arr.length; i++) {
Boolean(arr[i]);
if (Boolean(arr[i]) === false) {
newArr = arr.filter(Boolean);
} else
newArr = arr;
}
return newArr;
}
bouncer([7, "ate", "", false, 9]);Do I need another if condition maybe?
Hi All
Hope you all are doing great
Can someone please help me with "Using Objects for Lookups"
Hope you all are doing great
Can someone please help me with "Using Objects for Lookups"
@aashu1829 what is the problem?
I am not able to get what needs to be done here
@aashu1829 do you have an object set up?
@jkilgore07 You will see that in all the algorithmic challenges, your code is run once (and there's usually a sample test case inside, so you can check if it's likely correct), and then the function you are meant to implement is run by the test cases multiple times, with different input.
@Skidle yeah I have created the lookup
how can I share the code here
so that everyone can see
@Skidle Either use a loop and push all truthy elements to the new array, or use filter. Don't do both.
@aashu1829 you copy it and paste inside backticks ` (3 backticks on the each side of code)
@aashu1829 You need to assign the certain value in lookup object to result
@aashu1829 because so far result always is equal to
""
@aashu1829 On how to post code: http://forum.freecodecamp.com/t/markdown-code-formatting/18391
@Blauelf wow thanks! maybe you can also explain why it works if I only use one of them? It works but I don't understand why :(
skidle sends brownie points to @blauelf :sparkles: :thumbsup: :sparkles:
:star2: 2988 | @blauelf |http://www.freecodecamp.com/blauelf
@Blauelf ya i was thinking i had to use converToF(30) in the actual equation and keep changing the numbers in the argument, and have 6 different equations. Thanks alot
jkilgore07 sends brownie points to @blauelf :sparkles: :thumbsup: :sparkles:
:warning: jkilgore07 already gave blauelf points
~~~// Setup
function phoneticLookup(val) {
var result = "";
// Only change code below this line
var lookup={
alpha: "Adams",
bravo : "Boston",
charlie: "Chicago",
delta: "Denver",
echo: "Easy", foxtrot: "Frank"
};
// Only change code above this line
return result;
}
// Change this value to test
phoneticLookup("charlie");
~~~
@Blauelf I think I GOT IT thanks! :laughing: I was trying to explain my opinion here and suddenly I understood it xD
skidle sends brownie points to @blauelf :sparkles: :thumbsup: :sparkles:
:warning: skidle already gave blauelf points
@Skidle filter iterates an array, so you don't need to. So those two are about equivalent:
var newArr = arr.filter(Boolean);and
var newArr = [];
for (var i = 0; i < arr.length; i++) {
if (Boolean(arr[i])) {
newArr.push(arr[i]);
}
}but as if does its own conversion to boolean (just for evaluation), this would work, too:
var newArr = [];
for (var i = 0; i < arr.length; i++) {
if (arr[i]) {
newArr.push(arr[i]);
}
}and filter works the same, does not rely on true/false but truthy/falsy:
var newArr = arr.filter(function(x){ return x; });
@Blauelf hey, i have a question for you :)
@Blauelf thank you very much for the explanation!
skidle sends brownie points to @blauelf :sparkles: :thumbsup: :sparkles:
:warning: skidle already gave blauelf points
@Blauelf
table.selectAll("tbody .table-row").each(function(trData) {
var needed = trData.value.attribute;
$(this).on("click", function(e) {
document.location = "tesst.html#" + needed; // how do i get "needed" in here?
}
}
@darkflikk The
needed inside the callback is actually the needed from the scope it was defined in. So whatever value trData.value.attribute had at that time.
So it should work?
@darkflikk If that variable has meaningful content, it should. The file name "tesst.html" is interesting :D
Anyone here familiar with a
wait or time delay function? I'm using setTimeout but it isn't working the way I want
@Blauelf haha, do i need the variable "needed" or can i use the "trData"?
@Antiaccess What do you want? Some "wait 10s, then continue in the same function"? There can be only one code running at a given time, so that would block the browser for 10s, that's why we use asynchronous callbacks.
@darkflikk You can, sure, parameters are essentially like function-scope variables, just pre-initialized.
@Blauelf Just tested it. looks like i don't need the "needed" variabkle :D
okay, is there a good resource on asyncronous callbcks @Blauelf
?
@Blauelf
table.selectAll("tbody .table-row").each(function(trData) {
$(this).on("click", function(e) {
document.location = "tesst.html#" + trData.value.attribute;
}
}ok, now i know how it works. though i don't want to change document location but open a modal with a table that contains more information about that data set :)
@Blauelf thanks
darkflikk sends brownie points to @blauelf :sparkles: :thumbsup: :sparkles:
:star2: 2989 | @blauelf |http://www.freecodecamp.com/blauelf
you're almost at 3k ;)
@darkflikk Yes, now only points for @Blauelf for really solid advice. We don't wan't him to think he got it in vain.
@darkflikk But note that if you use the extra variable, it will use
trData.value.attribute of the definition time. If you use it directly, and trData has been changed in the meantime (probably not relevant here), you might get other values.
@darkflikk Me you can reward loosely, because I have 2985 and I wan't to beat him.
about @Masd925
:star2: 2985 | @masd925 |http://www.freecodecamp.com/masd925
@Blauelf you are wrong. it is relevant ;)
That's close.
hey everybody, could someone check one of my exercies from freecodecamp, cause there are 2 test that I can't go through :/
Hi all
@Blauelf at least i think so
@Blauelf would have to check
I have a question on JS: why does the JS documentation keep talking about "prototype" inside of array functions like here: Array.prototype.reverse()
and when you look at their examples they never use "prototype" in these function names...
@WAINGOR If you say
arr.slice(), your array arr does not have a property "slice". It is found on the prototype chain on Array.prototype, so you essentially call Array.prototype.slice, and set the this to arr, all that happens in a convenient arr.slice().
@theCember just post your code someone will be able to help
@Blauelf hmm, maybe it is not relevant. But since i am not 100% sure yet, i'll just use the
trData. Building a statistic site with graphs using dc.js
Okay, i put it here
aha! So do I understand correctly that this type of calling a function "borrows" a method from this so called prototype chain? @Blauelf
@WAINGOR Those functions exist once for all arrays, or all strings, on a common prototype. Whenever you say
new Array() (or an implicit version of that), the created object will have Array set as the constructor and Array.prototype installed in its prototype chain.
@Blauelf You seem busy, but if you get a moment (i'll be around for a bit) can you tell me how you might turn this simon game's timing events to work 'asynchronously':
https://codepen.io/antiaccess/pen/wogRwp
@Masd925 i will thank you whenever you can help me, so the competition between you and blauelf is fair. haha. (there, have some points)
darkflikk sends brownie points to @masd925 :sparkles: :thumbsup: :sparkles:
:star2: 2986 | @masd925 |http://www.freecodecamp.com/masd925
It is record collection exercie from javascript
Oh, totaly unintentional
@WAINGOR It's called delegation. What isn't found at the current object is delegated to its associated prototype object.
allright thanks
how do I send brownie points?
@theCember you can post your code directly to gitter, just follow the style guidelines https://github.com/FreeCodeCamp/FreeCodeCamp/wiki/Code-Formatting
@WAINGOR Mention someone (@Name) and use some variation of "thank you" in the same sentence.
@Blauelf thank you !
waingor sends brownie points to @blauelf :sparkles: :thumbsup: :sparkles:
:star2: 2990 | @blauelf |http://www.freecodecamp.com/blauelf
@Masd925 :P
@Blauelf why didnt you give him points with that?
i have problem with counting card in java script
```function reverseString(str) {
str.split("");
str.reverse();
str.join();
return str;
}
reverseString("hello");```
``` function reverseString(str) {
str.split("");
str.reverse();
str.join();
return str;
}
reverseString("hello");
var collection = {
"2548": {
"album": "Slippery When Wet",
"artist": "Bon Jovi",
"tracks": [
"Let It Rock",
"You Give Love a Bad Name"
]
},
"5439": {
"album": "ABBA Gold"
}
};
// Keep a copy of the collection for tests
var collectionCopy = JSON.parse(JSON.stringify(collection));
// Only change code below this line
function updateRecords(id, prop, value) {
//myObj.hasOwnProperty(checkProp)
if(prop=="artist"&&value!==""){
collection[id].artist = value;
} else if (prop==="artist"&&value===""){
delete collection[id].artist;
} else if (prop==="tracks"&&value!==""){
delete collection[id].artist;
} else if (prop==="tracks"&&value===""){
delete collection[id].tracks;
} else if (prop==="tracks"&&value!==""){
collection[id].tracks.push(value);
} else if (prop==="tracks"&&value!==""&&collection[id].hasOwnProperty(prop)){
collection[id].tracks.push(value);
} else if (prop==="tracks"&&value!==""&&collection[id].hasOwnProperty(prop)===false){
var tracks = [value];
collection[id] = tracks;
}
return collection;
}
oops im sorry
hmmm how do I send code in this chat again?
I messed up too XD
@WAINGOR use ``` before and after your code
var count=0;
function cc(card) {
// Only change code below this line
switch (card) {
case 2,3,4,5,6:
count=count+1;
break;
case 7,8,9:
break;
case 10,"J","Q","K","A":
count=-1;
break;
}
if(count>0){
return count;
}else {
return count;
} return "Change Me";
// Only change code above this line
}
// Add/remove calls to test your function.
// Note: Only the last will display
cc(2);
cc(7);
cc(9);
cc(7);
cc(8);
☨est
ah i see
@WAINGOR You should try to define each of those lines, that's what I did and it helped. Or you can do it all in one line, by combining the methods.
