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.
ok, let me try with your explanations
I will get back to you
question... in the middle statement of a for loop, can you update it ?
for example
I currently have for (i = 0; i < newStr.length; i++)
but later in my code I use newStr.pop() and newStr.shift()...so I was wondering, if each time I loop the newStr.length also gets updated?
@Janicekwing didja solve your challenge?
can anyone give me a hand, my icons are not showing...
well I resolved that issue earlier but I'm still working on the same challenge lol..
@Janicekwing ok
This is what I have
@Janicekwing Do you want to pair up on it?
Oh
How do you do it..?
do that*
@Janicekwing let me get a link
@Janicekwing can i send you a PM?
just did!
Guys, what does nesting arrays inside of each other do?
Does it help?
var myArray = [["Hello", 420], ["why", 69.1]];
Also how do i target one part of the array?
if you want to get "Hello" then write it like this
]
myArray[0][0] myArray[which element?][which item?]
Would that get hello and why>?
@John-freeCodeCamp myArray[0] gets you ["Hello", 420] then another [0] gets you the first value in that array "Hello"
Because first
0 select first element then second 0 pick "Hello" from that element
now how would i get why?
"why"
myArray[1][1]
Why not myArray[1][0]
@John-freeCodeCamp Oh sorry you are correctly
[1][1] will get 69.1
Array[which element do you want to select?][which value from this element?]
danke @MCTwoDigitZero @sjames1958gm
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hey
congats on 8K! @sjames1958gm
@Manish-Giri thanks
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@sjames1958gm Your profile picture is sad...
@dmsdesignz
can anyone give me a hand, my icons are not showing...
https://codepen.io/twistedkaos/pen/vZzNVg
can anyone give me a hand, my icons are not showing...
https://codepen.io/twistedkaos/pen/vZzNVg
please!
Did you open the image in a new tab?
"Open image in new tab"
Right click over icon/ image
it should have a .png or something at teh end of teh url
Use that url
@dmsdesignz did it work?
@dmsdesignz You need to use
The problem is, you need a unique icon for each day, so you need unique IDs.
.add() to get the skycon added. For example, add this after you .append() in your $.each loop:icons.add(document.getElementById(icon), icon)The problem is, you need a unique icon for each day, so you need unique IDs.
Anyway, the syntax is:
.add(canvas-element, weather-condition-from-dark-sky)
@SkyC0der Hey
Can you take a look at my search result? Link works but google only first name of character
is the darksky api free?
yes
Yea, you can just sign up for a key
No cost
I should do that
well I need to convert it to classes then...
its been really cool, learning lots!
ok I got this!
@sjames1958gm you on?
@SkyC0der does their script require you use the id's? do you know?
@dmsdesignz It doesn't require you to use the IDs, but you do need to provide a selector of some sort - (document.getElementsByClassName('icon')[0]) for example
@MCTwoDigitZero Sorry, stepped away
Its ok, was working on weather app
@SkyC0der for darksky api, I need a key right?
What happen if someone take look at my key in the code?
Normally you want to avoid exposing API keys on CodePen
var count = 0;
function cc(card) {
switch(card){
case 2:
case 3:
case 4:
case 5:
case 6:
count += 1;
break;
case 10:
case 'J':
case 'Q':
case 'K':
case 'A':
count -= 1;
break;
}
if(count>0){
card=" Bet";
}else if(count<=0){
card=" Hold";
} // If it possible use switch to achieve this like above????
return count + card;
}
cc(2); cc(3); cc(4); cc(5); cc(6);
If it possible use switch to achieve this like above????
@MCTwoDigitZero I used a proxy from github, its just a URL you append to the url
You mean to use that url instead of key?
Im going to use a key anyway.. dont know what happen if it got exposed
and added https://thingproxy.freeboard.io/fetch/ to the URL
I converted it to classes, but its still not working...
that proxie is very cool, I just fixed the HTTPS error i was getting for the background image!
Im going to use a key
Is it possible to set the state of every component in my array of JSX elements at the same time?
For instance is it possible to loop through every element and do
this.setState()
@njanne19, do you have a codepen set up for what you're trying to accomplish?
@marcusparsons https://codepen.io/njanne19/pen/BZOJmq?editors=1010
I've been working on this for a couple of hours. I have the cells clickable, but I wanna make it so I can change the
active property in every cell's state to off if I hit the clear button
function countTo(int) {
for (var i = 1; i < int + 1; i++) {
console.log(i);
}
}
@EricHasegawa is it running and just not producing the results you want?
@njanne19 The site I'm on just tells me it's wrong, I'm not seeing results displayed
@EricHasegawa I think if you just changed your loop to this:
```
function countTo(int) {
```
function countTo(int) {
Pardon
@njanne19 Oh shoot I'm sorry, it just wanted me to call the function myself and I didn't do that
Thanks anyways!
Ahh I see
@njanne19 Thanks!
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Sorry just sent twice to give you the points
Thank you, no problem
anyone know what this mean on codepen ?
Log Skipped: Sorry, this log was too large for our console. You might need to use the browser console instead.
Log Skipped: Sorry, this log was too large for our console. You might need to use the browser console instead.
@fdemaa It means your log is too big to fit inside the small codepen console. If you want to see what your log says, hit "Change View" then hit debug mode, then open the chrome console on your debug mode page
@njanne19 thanks !
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I
I'm so stuck on this stupid game of life
@njanne19 Do you know whats wrong with this?
$(document).ready(function() {
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(function(position){
});
}
Never mind
Hey, I just finished my Random Quote Machine. Can someone check it out to see if it's working properly? (The tweeting portion of it was working properly 2 seconds ago. I must have clicked on something because now it's not.)
https://codepen.io/Yuserah/pen/pwZgZy
https://codepen.io/Yuserah/pen/pwZgZy
Okay @njanne19, this has been my first foray into React this night, but I fixed your problem for you. What I did was loop through the available cells, make sure that they have a state property, and if they do, check to see if they're active. If they are active, call "cell.activate()" which will toggle them to be off. This will clear all of the cells that are currently active.
@YuserahN Twitter works but nothing is in text box
@MCTwoDigitZero Can you tell me why? It was displaying it properly in the Twitter text box but I think I accidentally changed something because now it's not. Is there anyway codepen let's you see the changes you made?
Lemme check
@YuserahN, you have too many spaces in your URL. You need to put
text right beside the ? in the URL like so
https://twitter.com/intent/tweet?text=
Also, you should set a default quote so that you can immediately click Tweet This. Otherwise, an error occurs
@marcusparsons Oh it's working now. Thanks.
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I'd like my first quote to be displayed on page load, without clicking the button, how can I do this?
https://codepen.io/twistedkaos/pen/ZyjZKG
https://codepen.io/twistedkaos/pen/ZyjZKG
Also consider using
encodeURIComponent() with strings being sent in a GET request (like what you're doing with Twitter) and not relying upon the browser to encode them.
document.getElementById("tweetQuote").setAttribute("href", "https://twitter.com/intent/tweet?text=" + encodeURIComponent(randQuote));
oh just set a default, I'd like it to be random...
Set the default to be a random quote lol
lol k
This is basic UI stuff man. You want your stuff to work out of the box
of course!
:)
@dmsdesignz but your profile pic is awesome man!
Where can I find an API that will give me my location? not latitude/longitude, like City, region..
@MCTwoDigitZero, if you feed Google Maps a latitude and latitude, it will deliver information like that
@marcusparsons That's awesome thank you]
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I use it in my weather app: http://marcusparsons.com/projects/weatherapp/index.html
@marcusparsons well Im working on my weather app
hm...
@njanne19, you're very welcome! It was pretty cool figuring this out because I've literally never worked with React before your codepen haha I had to decipher what was going on before I could do anything which is why it took a little bit to come up with a solution haha
function myReplace(str, before, after) {
var strArr=str.split(" ");
var afterArr=after.split("");
for(var i=0;i<strArr.length;i++){
if(strArr[i]==before){
if(strArr[i].toLowerCase()!=strArr[i]){
var sliced=afterArr.slice(0).join("");
var convertedAfter=afterArr[0].toUpperCase+spliced;
strArr[i]=convertedAfter;
return strArr.join("");
}
else{
strArr[i]=after;
return strArr.join;
}
}
}
}
myReplace("A quick brown fox jumped over the lazy dog", "jumped", "leaped");
@marcusparsons thanks man, simple photoshop stuff!
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@dmsdesignz, I am a n00b at photoshop man! But I think it still rocks anyways! haha
@Luyang2016, which challenge is this? Can you link it please?
@Luyang2016 you need to return
join(" ")
is this wrong ? i jus want to create and append a h1 lol
var parentt = document.getElementsByTagName("div")[0];
var referenceChild = document.getElementsByTagName("p")[0];
var newElement = document.createElement("h1");
var creationOfText = document.createTextNode("Hello World");
var result = parentt.insertBefore(newElement, referenceChild); this.props.cells[this.props.id] = this;
$(events).on("calcNextMove", this.calcNextMove());
$(events).on("makeNextMove", this.makeNextMove());this.props.cells[this.props.id] to equal the current Component that I am in. Am I doing it correctly or no?
function guessNumber(number) {
// Prompt the user for a number
var guess = prompt("Guess a number between 1 and 100");
// Convert their guess to a number using +
guess = +guess;
// Define base case
if (isNaN(guess) === true) {
return console.log("You got it! The number was " + number);
}
// Define recursive case with a function call
guessNumber(number);
}
// Call the function guessNumber() with an integer for an argument
guessNumber(7);
@EricHasegawa well for starters you shouldn't be doing return console.log
that's a no no
Second of all, because you're not returning a value (because you have a bad return statement) the recursion continues to happen
@njanne19 Okay thanks
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I'm trying to teach myself recursion using Codecademy and it's really rough, they said I had to use return console.log to pass one of the tests
Now my program is passing but it says it's wrong, when earlier it said it was wrong but it progressed me
@EricHasegawa that's odd, That's not a common practice
And it doesn't make any sense because console.log is not a command that returns any type of value, object, etc. For example, you can do this and it does nothing because
b is undefined:function a() {
return console.log('hi');
}
var b = a();
console.log(b);
@dmsdesignz You're going to have to loop through the <canvas> elements you create and add the icons to them individually. This is kind of the idea (but not the exact fix):
$.each($('canvas'), function(i, canvas) {
icons.add(canvas, $(canvas).attr('class'));
});
@SkyC0der :wave:
Hey @MCTwoDigitZero
So to set background-image like this
$("body").css("background-image", url(""));
@SkyC0der
yes
Try it:
$("body").css("background-image", 'url("https://placehold.it/600")');
@SkyC0der I see, thanks
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Didnt know I need a quote around url()
yeah, otherwise it's a variable
You can add all the CSS you want in curly braces like:
$("body").css({
"background-image": 'url("https://placehold.it/600")',
"background-position": "center center",
"background-size": "cover",
"min-height": "100vh"
});
Hm...
why
center center?
Good, this works with if statement
center horizontally and vertically
maybe redundant, I think if you only mention one value, the other will always be center
how can I extract all the images from the site https://www.templatemonster.com/demo/63629.html
i need some suggestions for the mutations challenge:
function mutation(arr) {
var lcArr = arr.toString().toLowerCase().split(",");
return lcArr[0].indexOf(lcArr[1]) !== -1;
}
mutation(["hello", "Hello"]);
is what i have so far. I am able to get everything right except for the challenges where the letters are in a different order and on those i am completely lost
i can't really think on anything we've touched on that relates on how to solve that
@M-C-Haker you don't have a loop?
@revisualize i guess that answer my question. i'll let "i" do the heavying lifting then
@M-C-Haker You need to check each character. not the whole string.
@revisualize yeah, i was kind of thinking something along those lines since the ones with the characters in different orders wer the ones i wasn't getting. i'll give it shot now
@SkyC0der hey, is it possible to use two API? would I have to use two $.getJSON? If I had darksky api there is no location like name, region
@MCTwoDigitZero Yes, you can use as many APIs as you want. You just have to make sure that the data comes back in the order you need
I see
@SkyC0der How did you get location with darksky api?
I used google maps API to get the city name
Hm..
Im using different API but they does have location like name,region but icon... not bad
Actually I have an idea
can anyone help me with calculator project
@SkyC0der Sorry since freeCodeCamp said
need a more efficient way of triggering event listeners and removeevents
Rule #1: Don't look at the example project's code. Figure it out for yourself.
Yeah, don't look at the example project :p
Search, find code samples, understand how to do what you want to do, write your code
anyway to remove a bunch of events at once
@SkyC0der Actually I dont need google maps API since Im using different api
Just need temperature and wind | humidity etc.. to load now
@SkyC0der Is it ok to use key for API in my code? :/
Yeah, it's fine @MCTwoDigitZero
Damn there are too many icons for if statements..
Weather Underground is pretty nice
I like the name of Dark Sky better
Im going to use Dark Sky after this
Just like random quote machines :p
can anyone help me with calc project?
Apixu => Dark Sky => Weather underground
I will create at least 2-3 weather apps
If you have to copy/paste if/else statements or make a huge switch statement, you are doing it wrong :)
var weatherIcon = {
"Clear": Skycons.CLEAR_DAY,
"Partly Cloudy": Skycons.PARTLY_CLOUDY_DAY,
"Mostly Cloudy": Skycons.CLOUDY,
"Rain": Skycons.RAIN,
"Light Rain": Skycons.RAIN,
"Light Thunderstorms and Rain": Skycons.RAIN,
"Sleet": Skycons.SLEET,
"Snow": Skycons.SNOW,
"Windy": Skycons.WIND,
"Overcast": Skycons.CLOUDY,
"Heavy Rain": Skycons.RAIN
};
make a lookup ^^
hm...
@JToddFL where do you need help in the project?
@SkyC0der then use if statements?
@MCTwoDigitZero The lookup avoids the need for if statements
Im confused lol
This is for background image
@Lumexralph I just need to turn off all click events
skycons.add('document.getElementById(iconDiv), weatherIcon[weatherCondition]);
@Lumexralph or figure something else out to do after someone runs calculations the first time
@Lumexralph I finished pretty much everything up until that last step
@MCTwoDigitZero So, if your weather summary/condition is
snow you do weatherIcon[weatherSummary] and it will look up the value for snow in the table. That can be a background image
@revisualize alright i thought i knew how to make it work but still kind of lost, getting the same errors with the loop
@SkyC0der ooh I get it, so if JSON object has
"snow" then weatherIcon[weatherSummary=>"snow"]
yes, and that returns "Skycons.SNOW" in the example above, but it could return background image instead.
if weatherSummary was snow then it will select an object from weatherIcon
Then you don't have to have like 15 if/else statements for all the weather conditions
@SkyC0der Thanks, you saved my time lol
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I just started doing that recently...whish I had known earlier
I see
saved me a lot of time... mind blown
weatherIcon[json["current"].condition.text] text==="Clear" then it will select "Clear"'s property from weatherIcon
Yeah looks correctly to me
Yeah, that should work
@SkyC0der you said that you wished you knew earlier but isn't it similar to Profile Lookup?
Yeah, but I didn't make the connection
I used a big switch statement and always stared at that code and hated it
lol
then :bulb: :bulb:
mind blown
Same, wonder why Profile lookup was not even in my mind
Thanks to you, I will probably remember it all time
I wonder what other lightbulbs haven't gone off yet
100% useful for weather app
in 10 years I'll laugh at my code :)
lol
in 1 year too probably lol
I will wait at least 5 years to look at my old code then
haha
:bulb:
:fire:
:hospital:
lol
Uggg, time for bed :( I will have to see your weather app tomorrow
@SkyC0der Sounds good, Night
gn :+1:
Not understanding what part of this json object should be giving me the link back to the article. I have a codepen if needed.
Object{
ns: 0,
size:34792,
snippet: "java applet is a small application",
timestamp: "2017 -05-30T",
title:"java servlet"
wordcount: 1610,
}
@jasonrest u can get the link from the title of the article
is that the Wiki viewer?
@hemakshis oh I have to build the link? @Manish-Giri yes
I thought it was a prop of the object that I just extract
@SkyC0der I am already laughing at my code
@jasonrest yes just convert all the spaces in the title's name with a underscore ('_')
@JToddFL but click event is important for the project
and append it to https://wikipedia.org/wiki/
@Manish-Giri sggggggggggm :smiling_imp: good morning
@hemakshis so what would the href look like?
lgm :smiling_imp: @Lumexralph
good morning
@Manish-Giri the urge to come hang out here ain't much as before
@Lumexralph yeah I know, same here
@Manish-Giri you make me want to come though :bow:
haha
https://wikipedia.org/wiki/java_servlet according to the example u gave
@Manish-Giri there's work and so much to be learnt, coming here is now a fraction of my time, sometimes I just view or pass by :smile:
:wave: guys
@kelechichinaka Brother, can you believe I didn't submit the first Andela assessment ?
@hemakshis right and for the sake of each unique article. just put the first part and the title. I will try it. thanks.
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:smile: y @Lumexralph
@kelechichinaka only did it all it showed that green click stuff but don't know how I missed it
function mutation(arr) {
var firstLcArr = arr[0].toLowerCase();
var secLcArr = arr[1].toLowerCase();
for (i = 0; i < secLcArr.length; i++) {
if (firstLcArr.indexOf(secLcArr[i]) < 0) {
return false;
}
return true;
}
}
mutation(["hello", "hey"]);
hello and hey should return false for some reason i am stuck on this. any ideas?
wow @Lumexralph
@kelechichinaka it almost happened the second time, finished it more than a week ago but had the urge to check what I did then out of curiosity I clicked submit assessment button and I was damn! thank God, I hope i'm still in time
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@M-C-Haker return true out of the loop
@Lumexralph which assessment
isn't -1 false though? @Lumexralph
u did another test @Lumexralph
@M-C-Haker your code was difficult to read though
@kelechichinaka yes baba mi
function mutation(arr) {
var firstLcArr = arr[0].toLowerCase();
var secLcArr = arr[1].toLowerCase();
for (i = 0; i < secLcArr.length; i++) {
if (firstLcArr.indexOf(secLcArr[i]) < 0) {
return false;
}
return true;
}
}
mutation(["hello", "hey"]);
var firstLcArr = arr[0].toLowerCase();
var secLcArr = arr[1].toLowerCase();
for (i = 0; i < secLcArr.length; i++) {
if (firstLcArr.indexOf(secLcArr[i]) < 0) {
return false;
}
return true;
}
}
mutation(["hello", "hey"]);
@Manish-Giri heard of Andela ?
i don't know why everyone else can seem to format properly but i can't
@M-C-Haker '''
:bulb: to format code use backticks! ``` more info
@M-C-Haker use 3 backticks not 1
@Lumexralph nope
who's Andela
@M-C-Haker click on the more info link
@Lumexralph Morning.
@Manish-Giri it's a software development company that recruits software developers or should I say prospective train them, pay them and outsource them to clients all over the world
@Masd925 Good Morning, how's vacation going?
can someone explain this
Array.prototype.reduce.call:var uniqueInOrder=function(iterable){
return Array.prototype.reduce.call(iterable, function(a,b) {
if (a[a.length-1] !== b) a.push(b);
return a;
}, []);
}
uniqueInOrder('AAAABBBCCDAABBB'); // should return ['A', 'B', 'C', 'D', 'A', 'B']
@Masd925 ES 2017 finally released
is the application still open @Lumexralph
@Manish-Giri 3 backticks?
@M-C-Haker
```
code
@Lumexralph Fine. Just heading for Finnish rapid chess championships. Two days without kids anywhere ;)
```
@Manish-Giri oh thanks
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@M-C-Haker you need to return true after the loop is done because your loop has to be done checking all the characters in
arr[0]
@Lumexralph if i return true after the loop everything else is incorrect...
@kelechichinaka always open just different cycles
@Masd925 :joy:
@Lumexralph Did you already print it and put it under your pillow?
@M-C-Haker
(firstLcArr.indexOf(secLcArr[i]) === -1 ) that's to say it found it so
u play chess? @Masd925
mehn i gats apply @Lumexralph
@kelechichinaka Yes.
@Lumexralph is there a fee for the bootcamp period?
i need that steady light and inrenet @Lumexralph
cool @Masd925 i've always wanted to learn chess
@Lumexralph mutation(["hello", "Hello"]) should return true is incorrect when i reformat the code in that way
@M-C-Haker http://jsbin.com/?js,console
post your code here then share the link
@Masd925 going as a competitor or spectator?
@kelechichinaka yeah applied again
can someone explain the
.call() method in this example: :point_up: July 8, 2017 12:43 PM
@Manish-Giri nope, no fee but I have to take care of my accommodation and transportation during the period
@Masd925 nah, i only have an html format I bookmarked
@kelechichinaka you know what keep applying and keep doing FCC and some Python along the line
is what i have though i'm not sure why there is not output @Manish-Giri
@longnt80
call is a method of the Function object, used to call a function on an iterable/object that doesn't have that method
@M-C-Haker don't you need to
.split() the strings?
@Lumexralph so in this case it can call the
.reduce() method to work with a string?
@M-C-Haker
function mutation(arr) {
var firstLcArr = arr[0].toLowerCase();
var secLcArr = arr[1].toLowerCase();
for (i = 0; i < secLcArr.length; i++) {
if (firstLcArr.indexOf(secLcArr[i]) === -1) {
return false;
}
}
return true;
}
mutation(["Hello", "hello"]);
@longnt80 yes
@Manish-Giri i wouldn't think so... when i specify the arr[0] it is referring directly to a string in that location and if i was splitting it would mean that i had taken it from array made it a string and split it again into an array, right? i dont know lol
@longnt80 remember that,
string and array are similar, they're both iterable and they're both sequences of characters and elements
@M-C-Haker okay then
@Lumexralph Playing.
also move the
return true outside the for loop.
@Lumexralph I know that part, I was confused because reduce is an array method and wouldn't work with a string
@Manish-Giri yes that is the problem. i noticed when @Lumexralph posted that i was still in the loop thanks
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it works now
```
function mutation(arr) {
var firstLcArr = arr[0].toLowerCase();
var secLcArr = arr[1].toLowerCase();
for (i = 0; i < secLcArr.length; i++) {
if (firstLcArr.indexOf(secLcArr[i]) < 0) {
return false;
}
}
return true;
}
mutation(["hello", "hey"]);
@Manish-Giri but the 3 backticks don't for me!
where's the closing set of 3 ```
```
code
```
@Masd925 I wish you beat them all to make up for the diving championship.....all the best
@longnt80 the question is how does
reduce work
ah i see. @Manish-Giri and after reviewing the other solutions there is one where they split but i have no idea what's going on there, that's the "advanced solution"
function mutation(arr) {
return arr[1].toLowerCase()
.split('')
.every(function(letter) {
return arr[0].toLowerCase()
.indexOf(letter) != -1;
});
}
.every() returns true if the callback you pass to it, returns true for every element in the array you're using .every() on @M-C-Haker
try a simpler example first
@Lumexralph reduce is to apply a function to each item and a accumulator value and return a single value (accumulator), right?
[2, 4, 6].every(num => num % 2 === 0);
@M-C-Haker
this will return true, can you guess why?
should i initiate my ready() function at the top or bottom of my js file
is there a best practice?
@Lumexralph if in the example above, I use the reduce method on
iterable, it wouldn't work because iterable is a string:return iterable.reduce(function(a,b) {
if (a[a.length-1] !== b) a.push(b);
return a;
}, []);
@longnt80
[0, 1, 2, 3, 4].reduce(
function (
accumulator,
currentValue,
currentIndex,
array
) {
return accumulator + currentValue;
}
);
//The callback would be invoked four times, with the arguments and return values in each call being as follow
@Manish-Giri because there is no remainder when divided by 2?
@M-C-Haker yes
@Manish-Giri dude that just made my night tbh. thanks..
m-c-haker sends brownie points to @manish-giri :sparkles: :thumbsup: :sparkles:
:warning: m-c-haker already gave manish-giri points
:+1:
@Lumexralph I think I can understand how
reduce() works, what I haven't grasped is the call() method
@longnt80 when you use
call it uses a function on the this object, it only got the function from the Array.prototype object
some challenge i breeze through. other's not so much,but it's nice to get those one offs that confirm you're at least learning something! I could use more of those kind of syntax/theory tests, i think. Do you have any good references? @Manish-Giri
@M-C-Haker yup, try out hackreactor prep
the free course
i definitely will, they just got a bookmark. thanks again
all the best!
@longnt80 it's just a kind of hack so to speak, ordinarily,
reduce should not work on string but call, apply method gave that power to us, call is a method of the Function object, even when reduce was created for array, it still is a function, that made it possible to be able to use call on it,
@longnt80 so what
call did was just allowed you to be able to use reduce on the string
@Lumexralph thanks man
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@Manish-Giri i want to use
OOP for my pomodoro clock
nice
@longnt80 you're welcome
@Manish-Giri motivation from Python class, it makes the code look so easy compared to procedural way
@Manish-Giri still miss the lecturers though :smile: cool guys and I want to improve on my Python but JS is in the way, what do you think I can do :worried:
Anyone stuck?
i'm bored
hey anyone can point to some documentation regarding using 'this' in React?
@rybka02 you can explain 'this' in react in a way that I would use it with confidence
Sorry. I don't use react. I could explain its use in Javascript or Jquery.
@rybka02 I understand it in a basic way
but tnx anyways
maybe you can explain anyways, maybe intermediate and advanced use cases
@Giveback007 so
this in React is different from this in vanilla JS?
@longnt80 I want to know the differences, and maybe use cases that should be noted in react
I assume it's the same for the most part
assumptions are assumptions
@Giveback007 I haven't learned React but I also assume it would be the same as regular JS
@Giveback007 it's the same
a (stateful) component in React is just like a class
the
this behaves the same way as you would expect to, with regular JS classes
@Manish-Giri what is the 'get' business in react
should I always try to use this.methodName in react classes?
should I always try to use this.methodName in react classes?
@Giveback007 get business?
that's not react specific
get is just the pattern for creating a getter in JS
@Manish-Giri ahh tnx
hudge gaps in my knowledge
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I don't think you'll need to use
get in react apps
but I might be wrong
whoa 6213 start. You are busy in here :smile:
haha
lol
:bow: master teach me!!
i'm no master buddy
I'm also learning..doing redux at the moment.
other regulars like @sjames1958gm know much more than me
@Manish-Giri (whispers quietly) ~master~
rofl
:joy:
lol
@Manish-Giri what did you use to learn react?
@Giveback007 the official docs
they're very good
I keep getting bored sooo fast when I'm learning, I can't stay focused
I did the first fcc react project in 2-3 hours (I think), but to learn ReactDOM.render took a week ... because it's soooooo booooring
Nesting for Loops
function multiplyAll(arr) {
var product = 1;
// Only change code below this line
for(var i=0;i<arr.length;i++){
for (var j=0; j < arr[i].length; j++){
product*=arr[i][j];
}
}
// Only change code above this line
return product;
}
// Modify values below to test your code
multiplyAll([[1,2],[3,4],[5,6,7]]);haha i finished the challenge but boy wtf just happened i don't get it is anyone care to explain
how did you write the code if you don't get it?
@munkhmanlai do you know how arr.length works?
@Manish-Giri there is a 2d loop example right in fhe exercise - its almost copypaste except the return and the thing inside the loops :D
yeah it means whatever the length run the code @Giveback007
@alpox oh yeah probably
@munkhmanlai
It means you get the length of the array
for every 1 run of the outer loop the inner loop runs the j < arr[i].length
@Giveback007 for example,
```
for(i=0; i<5; i++){
```
for(i=0; i<5; i++){
eg: [ [1,2,3], [a,b,c], [4,5,6] ]
arr[0] aka arr[i] on first run of i loop will be [1,2,3]
the inner loop will then iterate trough that loop
so arr[i][0] will be 1
aka arr[i][j] first run of i loop and first run of j loop
you can figure out the rest this way by imagining step by step how the loop travels
I hope that made sense
what am i doing wrong here? trying to concat. the beginning of the url with the object title.
$('#output').prepend("<li><a href=" "wikipedia.com/wiki/" + test[i].title + ">" + test[i].title + "</a><br/><span>" + test[i].snippet +"</span></li>");" "wikipedia.com/wiki/"
this looks wrong
without those quotes then....
$('#output').prepend("<li><a href=" wikipedia.com/wiki/ + test[i].title + ">" + test[i].title + "</a><br/><span>" + test[i].snippet +"</span></li>");
hey
'''$.getJSON(gooloc, function(loc){
$("#locate").html(loc.address_components.results.long_name["country"]);
var city = loc.address_components["administrative_area_level_1"];
var state = loc.address_components["country"];
var province = loc.address_components["administrative_area_level_2"];
$("#locate").html(loc.address_components.results.long_name["country"]);
var city = loc.address_components["administrative_area_level_1"];
var state = loc.address_components["country"];
var province = loc.address_components["administrative_area_level_2"];
$("#locate").html(city); '''. Hello! Is this code well writted?? I cant get the locatión name ....:bulb: to format code use backticks! ``` more info
''' $.getJSON(gooloc, function(loc){
$("#locate").html(loc.address_components.results.long_name["country"]);
var city = loc.address_components["administrative_area_level_1"];
var state = loc.address_components["country"];
var province = loc.address_components["administrative_area_level_2"];
$("#locate").html(loc.address_components.results.long_name["country"]);
var city = loc.address_components["administrative_area_level_1"];
var state = loc.address_components["country"];
var province = loc.address_components["administrative_area_level_2"];
$("#locate").html(city); ''':bulb: to format code use backticks! ``` more info
``` $.getJSON(gooloc, function(loc){
$("#locate").html(loc.address_components.results.long_name["country"]);
var city = loc.address_components["administrative_area_level_1"];
var state = loc.address_components["country"];
var province = loc.address_components["administrative_area_level_2"];
$("#locate").html(loc.address_components.results.long_name["country"]);
var city = loc.address_components["administrative_area_level_1"];
var state = loc.address_components["country"];
var province = loc.address_components["administrative_area_level_2"];
$("#locate").html(city); ```. Sorry i am with the mobile..... 
@luccifer00 better use dot. for example: var state = loc.country;
@vittorioVT , in the google example, i think i have to write from the root.... i will try that
Maybe i have wrong write the http API
var gooloc ="https://maps.googleapis.com/maps/api/geocode/json?latlng="+ lat + "," + long +"&key=AIzaSyBUzuWvyNu66-dU5DW8DfMqNQ87JgFPCUs";
i should add something at the end??? I just follow the html example....
should i add ?callback?=?
@luccifer00 sometimes at the end you need to add a key
@vittorioVT yes i know, the lat and long and keys are mine.... it isnt the example key
@luccifer00 If in your example isn't key, then it isn't necessary. I used a source where a unique key was required
@luccifer00 your function ( $.getJSON(darkSky1, function(json){...) have already timezone, latitude and longitude, why do you need var gooloc else?
Hi I am working on the wikipedia viewer. I was wondering if I can use a
<form> and a submit button. To start the search. Or will that mean that the page will be reloaded?
@vittorioVT in that function i tried to get timezone, but i return nothing (empty field) on html box. That is the reason i need to use google api. Anyway i dont understand why $("#locate").html("momo"); dosent return nothing, even "momo" was a city var, it is like the $(#locate") was ommited for some reason...
maybe i should chang that for .add??
In the darksky website said that time zone is required, but i can not figure out how to get it without google api
@knrt10 thank you mate
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@luccifer00 you don't need the timezone for darksky, just lon and lat
hi all, i am trying to implement a feature on tumblr where upon hover, the title will be rearranged to form another word. the below code works fine when i tested it on my other sites (not tumblr) but doesnt animate on tumblr. any idea why?
.name-container{
display: inline-block;
border-bottom: 1px dotted black;
margin-top: -10px;
font-size: 15px;
//background-color: pink;
}
span.char3:hover{
transform: translateX(0);
}
span.char2:hover{
transform: translateX(0);
}
span.char4:hover{
transform: translateX(0);
}
span.char5:hover{
transform: translateX(0);
}
span.char6:hover{
transform: translateX(0);
}
}
span{
display: inline-block;
margin-left: 0.5px;
}
span.char2{
transform: translateX(3.54em);
transition: transform 500ms;
}
span.char3{
transform: translateX(0.34em);
transition: transform 500ms;
}
span.char4{
transform: translateX(0.32em);
transition: transform 500ms;
}
span.char5{
transform: translateX(0.32em);
transition: transform 500ms;
}
span.char6{
transform: translateX(-3.21em);
transition: transform 500ms;
}
$(document).ready(function(){
$('#search-btn').click(function(){
var keyword =$('#keyword').val();
var url = "https://en.wikipedia.org/w/api.php?action=opensearch&search="+keyword+"&format=json&callback=?";
//api call
$.ajax({
type: "GET",
url: url,
async: false,
dataType: "json",
success: function(data){
//retriving data
for(var i= 0; i<data[1].length; i++){
//sending markups to the ul tag with data
$('#results').prepend("<li><a href="+data[3][i]+">"+data[1][i]+"</a><p>"+data[2][i]+"</p></li>");
}
},
error: function(errorMessage){
//in-case of error
alert("error");
}
});
});
});I can't retrieve the data into html.
Sometimes it shhows for a split second, but then the whole body goes white....
@JoeTinnySpace check if you use a submit button from a form, you have to use preventDefault
Otherwise the page refresh
Otherwise the page refresh
@Chrono79 I just noticed, now the console.log doen't work either. But was working before ... Can you look into the code? https://codepen.io/CallMeJoe/pen/JJmjxj?editors=1011
@JoeTinnySpace add
e.preventDefault(); below $('#search-btn').click(function(e){
@Chrono79 wow, thanks
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:+1:
M
@Chrono79 why isn't the
for(var i= 0; i<data[1].length; i++){
// sending markups to the ul tag with data
$('#results').prepend("<li><a href="+data[3][i]+">"+data[1][i]+"</a><p>"+data[2][i]+"</p></li>");
}doesn't work, after this $('#results').htmll('');
alright got it
stupid me!
M
why isn't there a semicolon after the last expression:
for (i = 0; i<10; i++)?
@MichielHuijse because it isn't needed
@MichielHuijse Because the semi-colons are only to seperate the values inside the for loop definition
They are not the same as statement ending semi-colons
They are not the same as statement ending semi-colons
@Chrono79 but if you paste a semicolon the code will produce an error
for ([initialization]; [condition]; [final-expression])
statement
Sometimes rules is rules, that is how it is defined
if (a < b) you don't put a semicolon inside those parentheses either
@sjames1958gm so they are expressions instead of statements
thanks for the quick reply both! @Chrono79 @sjames1958gm
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:+1:
@MichielHuijse yw
That for loop format is from the early 70s when C was invented.
it is kind of confusing for me. I thought it would be something like declaring variables. like so:
for (i = 0, i<10, i++;) :D
@MichielHuijse The for loop can be converted to a while loop. You can see each piece here.
var i = 0;
while (i < 10) {
<body>
i++;
}
hi can anyone tell me the meaning of
for(int num:numbers)
what is num:numbers here?
Just a minor detail, think I will get used to it.
@vivekranjan92 for in loop in java
@MichielHuijse :)
@SweetCodingInc didn't get you
@vivekranjan92 that's not javascript, that's java (or some other language with that syntax)
@Chrono79 yes I know
thought some genius will help me
@Chrono79 yeah thanks but can learn from googling it... I want some one to explain me
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afaik numbers is an array of integers there, and num is the var name you can use to hold them
what is it you don't get? Maybe with that we can help you better
I know very little of java tho
i was looking the code to find the duplicate in an array
there i found this thing
@Chrono79 np that will be fine if you explain me a bit
and you have the full code?
Hello everybody! Can anyone explain me why does my code not work?
function truthCheck(collection, pre) {
// Is everyone being true?
collection.forEach(function(element) {
if (pre in element === false)
return false;
});
return true;
}
truthCheck([{"user": "Tinky-Winky", "sex": "male"}, {"user": "Dipsy"}, {"user": "Laa-Laa", "sex": "female"}, {"user": "Po", "sex": "female"}], "sex");If every object contains second argument ("sex") function should return true else false.
How could I clear the content of <h1></h1>
to fill it from another
to fill it from another
@vivekranjan92
int num : numbers
num is the loop variable and will be assigned a value from numbers for each loop iteration
int num : numbers
num is the loop variable and will be assigned a value from numbers for each loop iteration
Hi all I am going nuts here. The code here below logs NaN.... But then if I replace the last line with console.log(typeof newAr) it logs number!!!! What duh hellllllll
var myArr1 = [2, 2, 2, 2, 2];
var newArr = myArr1.reduce(
function(val, idx) {
console.log(idx);
console.log(val);
return myArr1[idx] += val;
});
console.log(newArr);
@GeorgeII The return inside the forEach does nothing other than go to the next loop iteration
@WAINGOR
typeof NaN
"number"
@WAINGOR the arguments of reduce's callback aren't those
@WAINGOR Welcome to the weird world of JavaScript, in javascript
typeof NaNis a number
@sjames1958gm ty
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looooool
How could I clear the content of <h1></h1>
to fill it from another with a click on button
to fill it from another with a click on button
but how is 2+2+2+2 not a number?
@WAINGOR idx is not and index it is a value from the array. val is the accumulator
@sanket143 If you are using jquery there is the empty() function.
@sjames1958gm that makes sense. But still, how does it log NaN? I suspect it is because I try to reach an item that isnt there... (very quickly this code says myArr1[6] += val , and myArr1 only has 5 items in it...
@WAINGOR where are you running this code?
in the browser
How? devtools console?
yes
ahh yes I see that reduce can even change the original array! as a matter of fact, it does exactly that in this example
undefined is the result of the final statement and console.log() returns undefined
@WAINGOR When you get to element [4] it has the value of 6 and is past the end of the array.
@sjames1958gm is doesnt log undefined in my browser... do you have JS harmony activated @ chrome? I do.. idk if that makes a difference
@sanket143 just do this to replace the current quote
roll.innerHTML = ourData[count];
roll.innerHTML = ourData[count];
okay
@WAINGOR paste your code there: http://www.pythontutor.com/javascript.html#mode=edit
@WAINGOR test gets logged then it shows the result of the last statement which is the return from console.log which is always undefined in chrome
console.log("test")
test
undefined
@sjames1958gm idk about the above, but when I drop the code into a .html file and run it in the browser it logs NaN :)
thats cool .... @sjames1958gm thanks
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@WAINGOR Yes, NaN is the result of the statement (you will only see undefined in the console)
function(acc, val) {
console.log(acc);
console.log(val);
return acc + val;
}
If you want to sum the values in the array. And reduce doesn't return an array (unless the function passed to it does)
helpful as always, thanks @sjames1958gm
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@WAINGOR :+1:
Profile Lookup
We have an array of objects representing different people in our contacts lists.
A lookUpProfile function that takes firstName and a property (prop) as arguments has been pre-written for you.
The function should check if firstName is an actual contact's firstName and the given property (prop) is a property of that contact.
If both are true, then return the "value" of that property.
If firstName does not correspond to any contacts then return "No such contact"
If prop does not correspond to any valid properties then return "No such property"
var contacts = [
{
"firstName": "Akira",
"lastName": "Laine",
"number": "0543236543",
"likes": ["Pizza", "Coding", "Brownie Points"]
},
{
"firstName": "Harry",
"lastName": "Potter",
"number": "0994372684",
"likes": ["Hogwarts", "Magic", "Hagrid"]
},
{
"firstName": "Sherlock",
"lastName": "Holmes",
"number": "0487345643",
"likes": ["Intriguing Cases", "Violin"]
},
{
"firstName": "Kristian",
"lastName": "Vos",
"number": "unknown",
"likes": ["Javascript", "Gaming", "Foxes"]
}
];
function lookUpProfile(firstName, prop){
// Only change code below this line
for(i=0;i<contacts.length;i++){
if (firstName,prop==contacts.firstName){
return contacts;
}
}
// Only change code above this line
}
// Change these values to test your function
lookUpProfile("Akira", "likes");How should i approach this challenge i am confused as fuck when it comes to loops and object
@munkhmanlai - the first thing to realize is that
contacts is an array, so you have to use array indexing in some form to access the objects within the array. You are generating the index with your variable i, but you aren't using it.
@munkhmanlai firstName, prop are two separate values passed to the function
And firstName is a property on the contact in the array, not the array itself
And firstName is a property on the contact in the array, not the array itself
@khaduch but i have to use for loop right
@sjames1958gm so check them separately then
@munkhmanlai You should use a for loop
Yes, as the instructions say.
Yes, as the instructions say.
@sjames1958gm damn it is hard
@sjames1958gm in for loop, i am using IF to check right how should i check if firstName is in my array
?
@munkhmanlai Takes time to learn these new concepts.
@sjames1958gm did u struggle when u are learning these or was it just breeze
@munkhmanlai Each contact has a firstName property which you need to compare to the parameter
@munkhmanlai I am not a general case - I have been programming in other languages already
@sjames1958gm yeah i know but how to compare is my confusion
@munkhmanlai
var contacts = [
{
"firstName": "Akira",
"lastName": "Laine",
"number": "0543236543",
"likes": ["Pizza", "Coding", "Brownie Points"]
},
{
"firstName": "Harry",
"lastName": "Potter",
"number": "0994372684",
"likes": ["Hogwarts", "Magic", "Hagrid"]
},
{
"firstName": "Sherlock",
"lastName": "Holmes",
"number": "0487345643",
"likes": ["Intriguing Cases", "Violin"]
},
{
"firstName": "Kristian",
"lastName": "Vos",
"number": "unknown",
"likes": ["Javascript", "Gaming", "Foxes"]
}
];
function lookUpProfile(firstName, prop){
// Only change code below this line
for(i=0;i<contacts.length;i++){
if (firstName==contacts[i].firstName){
return contacts[i];
}
}
// Only change code above this line
}
// Change these values to test your function
lookUpProfile("Akira", "likes");
@kr5hn4 aah i seee thanks
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@khaduch @sjames1958gm how many loops do i have to use?
1
review all past object's related challenges
why
course++; is not working ?? https://codepen.io/gr8ayu/pen/yXRLep?editors=1010
on clicking correct button
@munkhmanlai - you only need one loop, all of the condition testing takes place within one loop.
@khaduch thanks
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@Gr8ayu YOu have both click handlers on pass, so it goes up then goes down
lol
good catch
:)
@khaduch
var contacts = [
{
"firstName": "Akira",
"lastName": "Laine",
"number": "0543236543",
"likes": ["Pizza", "Coding", "Brownie Points"]
},
{
"firstName": "Harry",
"lastName": "Potter",
"number": "0994372684",
"likes": ["Hogwarts", "Magic", "Hagrid"]
},
{
"firstName": "Sherlock",
"lastName": "Holmes",
"number": "0487345643",
"likes": ["Intriguing Cases", "Violin"]
},
{
"firstName": "Kristian",
"lastName": "Vos",
"number": "unknown",
"likes": ["Javascript", "Gaming", "Foxes"]
}
];
function lookUpProfile(firstName, prop){
// Only change code below this line
for(i=0;i<contacts.length;i++){
if (firstName==contacts[i].firstName){
return contacts[i].firstName;
}else return "No such contact";
if (prop==contact[i].likes){
return contacts[i].likes;
}else return "No such property";
}
// Only change code above this line
}
// Change these values to test your function
lookUpProfile("Akira", "likes");it doesn't giving me likes or the prop?
@munkhmanlai you are comparing a property name to a property value.
@munkhmanlai YOu need to check the property only when the firstName matches
@Gr8ayu - you have two event handlers for
.pass and none for .fail - so when you click, it increments and then decrements your value and updates it twice. (I see that someone answered while I wasn't looking... :) )
@sjames1958gm likes is property name isn't it?
@sjames1958gm or property value?
@munkhmanlai
prop is a variable with a property name.
You need to check if the property exists on the contact - https://www.freecodecamp.com/challenges/testing-objects-for-properties
contact[i].likes this result of this expression is a property value.prop is a variable with a property name.
You need to check if the property exists on the contact - https://www.freecodecamp.com/challenges/testing-objects-for-properties
@Chrono79 yes i have
hey guys, I'm working on creating a javascript game that combines a 2d classic rpg dungeon crawler with 3 match puzzle game like Candy Crush. I've gotten my assets in place (just placeholders for now), but I'm wondering if I should choose a game engine to work in or try to create my own, since my game will be combining two game types. What do you guys think?
@sjames1958gm @khaduch thanks
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@Chrono79 Do you want full code?
@AmitP88 phantom.js is popular to make games
@vivekranjan92 you can edit your message
@shivamg11000 thanks, i'll check it out :)
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@munkhmanlai thank you so much for your choice of language. It rllly cheers my day up here in Holland
@Gr8ayu thanks i was not aware of it
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anybody who code reactjs and angular both
how these websites are made , they scroll whole screen at once ??
help guys! i´m doing a challing in javascript now, the output is correct, but the site says it is not correct
function titleCase(str) {
str = str.split(" ");
var arraySize =str.length;
var arrayStr;
var newStr = "";
for (var i = 0; i < arraySize; i++){
arrayStr = str[i].charAt(0).toUpperCase() + str[i].substr(1).toLowerCase();
newStr = newStr + " " +(str[i].charAt(0).toUpperCase() + str[i].substr(1).toLowerCase()).toString();
}
return newStr;
}
titleCase("I'm a little tea pot");
@Gr8ayu fullPage.js is a plugin that lots of sites use to do that: https://github.com/alvarotrigo/fullPage.js
Here's a codepen showing how to do it: https://codepen.io/alvarotrigo/pen/qqgPNy
Here's a codepen showing how to do it: https://codepen.io/alvarotrigo/pen/qqgPNy
@SkyC0der thanx
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@fyudi probably an extra space at the front.
@fyudi easier to put the modified word back into the array and join at the end
@sjames1958gm wow thanks :))
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god this JS object is making me mad
@sjames1958gm do you know how to get refs from inside the render function? I was trying to pass it via componentdidmount state but it is not getting set
@munkhmanlai like
export default class Timeline extends Component {
constructor(props) {
super();
this.arr = this.generateTimelineArray();
this.state = {el : 'empty'};
}
componentDidMount() {
// it is a regular DOM node
this.setState({
el: this.refs.el
});
console.log('------------------');
console.log(this.state.el)
}
render() {
const timeList = list.map((element) =>
<TimelineElement element={element}/>
);
return (
<div className="timeline__container" >
<div className="timeline__container--line" ref="el" >
</div>
{timeList}
</div>
);
}
Can anyone explain WTF :angry: is going on here?
Testing Objects for Properties
Testing Objects for Properties
// Setup
var myObj = {
gift: "pony",
pet: "kitten",
bed: "sleigh"
};
function checkObj(checkProp) {
// Your Code Here
if(checkObj.hasOwnProperty(checkProp)){
return myObj(checkProp);
}else
return "Not found";
}
// Test your code by modifying these values
checkObj("gift");
@munkhmanlai checkObj is your function's name
your object's name is myObj
your object's name is myObj
it checks if your object has gift
and then return the value of it
if the the key is not in the object it returns not found
anyone can give me a hand on react ? :(
@Chrono79 i really don't get wtf is going on after function
after function you are calling the function
all the functions have to be called
"gift is the value you pass to the function - checkProp
下面的代码将输出数组 arr 的每个元素到控制台：
var arr = [10,9,8,7,6];
for (var i=0; i < arr.length; i++) {
console.log(arr[i]);
}
记住数组的索引从零开始的，这意味着数组的最后一个元素的下标是：数组的长度 - 1。我们这个循环的 条件 是 i < arr.length，当 i 的值为 长度-1 的时候循环就停止了
var arr = [10,9,8,7,6];
for (var i=0; i < arr.length; i++) {
console.log(arr[i]);
}
记住数组的索引从零开始的，这意味着数组的最后一个元素的下标是：数组的长度 - 1。我们这个循环的 条件 是 i < arr.length，当 i 的值为 长度-1 的时候循环就停止了
@munkhmanlai
if(checkObj.hasOwnProperty(checkProp)){ <- this line is wrong
I dont understand why .length is -1.
Is it should be 5?
@2895388807 wheredo you get the -1 from
@Chrono79 yeah i fixed it to myObj.hasOwnProperty(checkProp)
@Chrono79 but how do u return the value of myObj property if it is true
description
this sentence is right . I just dont under the description.
@2895388807
var myObj = {
gift: "pony",
pet: "kitten",
bed: "sleigh"
};
function checkObj(checkProp) {
// Your Code Here
if(myObj.hasOwnProperty(checkProp)){
return myObj(checkProp);
}else
return "Not found";
}
// Test your code by modifying these values
checkObj("gift");
@munkhmanlai Also watch the casing for
To access the property, refer to: https://www.freecodecamp.org/challenges/accessing-objects-properties-with-bracket-notation
"Not Found", as "Not found" (lower-case 'f') won't pass.To access the property, refer to: https://www.freecodecamp.org/challenges/accessing-objects-properties-with-bracket-notation
@munkhmanlai thank you
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var myObj = {
gift: "pony",
pet: "kitten",
bed: "sleigh"
};
function checkObj(checkProp) {
// Your Code Here
if(myObj.hasOwnProperty(checkProp)){
return myObj(checkProp);
}else
return "Not found";
}
// Test your code by modifying these values
checkObj("gift"
the description mean when i's length is -1 it cycle stoped.
@munkhmanlai plz show me the title. I just pass this class.
let me see maybe help you
@2895388807 Testing Objects for Properties
code outputs correctly so whats wrong?
@munkhmanlai take off else and try
@IggySmith It shouldn't be
gear += addGear
@thomlom then?
@IggySmith You want to set the number of gear, not to add the number of gear :)
According to your code :
myBike.setGear(1)
myBike.getGear() // evaluates to 1
myBike.setGear(4)
myBike.getGear() // evaluates to 5
myBike.setGear(3)
myBike.getGear() // evaluates to 8Instead it should be :
myBike.setGear(1)
myBike.getGear() // evaluates to 1
myBike.setGear(4)
myBike.getGear() // evaluates to 4
myBike.setGear(3)
myBike.getGear() // evaluates to 3
@thomlom thanks
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Hi all, a little question on reduce here. I am trying to make the excercise "Render Images from Data Sources " (JSON API's and AJAX) using map instead of .forEach . Does anybody know why this code returns "<div><img src='<div><img src='<div><img src=" as the beginning of the string? I would say that at the beginning of each loop it would prepend that string to the rest...
var json =
[
{
"id": 0,
"imageLink": "https://s3.amazonaws.com/freecodecamp/funny-cat.jpg",
"altText": "A white cat wearing a green helmet shaped melon on it's head. ",
"codeNames": [
"Juggernaut",
"Mrs. Wallace",
"Buttercup"
]
},
{
"id": 1,
"imageLink": "https://s3.amazonaws.com/freecodecamp/grumpy-cat.jpg",
"altText": "A white cat with blue eys, looking very grumpy. ",
"codeNames": [
"Oscar",
"Scrooge",
"Tyrion"
]
},
{
"id": 2,
"imageLink": "https://s3.amazonaws.com/freecodecamp/mischievous-cat.jpg",
"altText": "A ginger cat with one eye closed and mouth in a grin-like expression. Looking very mischievous. ",
"codeNames": [
"The Doctor",
"Loki",
"Joker"
]
}
];
var Y = json.reduce(function(accumulator,currentvalue) {
return "<div><img src='" + accumulator + currentvalue.imageLink;
// Only change code above this line.
},"");
console.log(Y);
excuse me I mean .reduce not map :)
you dont have closing tags
return "<div><img src='" + accumulator + currentvalue.imageLink"'/></div>";
@munkhmanlai Use bracket notation, parentheses are for functions/methods, not to get object's properties
Review https://www.freecodecamp.org/challenges/accessing-objects-properties-with-variables
Review https://www.freecodecamp.org/challenges/accessing-objects-properties-with-variables
@gadzet that syntax is not valid... a + needs to come after .imagelink , and I tried that already :)
is gets the same result
var runIt = function (a) {
console.log(a);
a();
}
@WAINGOR Every loop it adds that string to the front of the existing string. You should do
return accumulator + "<div><img src='" + currentvalue.imageLink + "></div>";
return accumulator + "<div><img src='" + currentvalue.imageLink + "></div>";
@WAINGOR I think accumulator and currentValue are not set
@challenger11 Well it is all of those, it is a parameter, operates as a variable and contains the value passed to the function in the first argument.
in this code it assumes that the value passed is a function so a() is calling the passed in function
in this code it assumes that the value passed is a function so a() is calling the passed in function
@sjames1958gm thanks but I get it and I don't get it , because I need to practice more.
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@challenger11 The a() is unique to the case where the value passed is a function.
@sjames1958gm your sense of logic is gargantuan. The force is is definitely strong with you. Thnx this works perfectly
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@sjames1958gm is this a() common in javascript? I mean is it used frequently as u said its a unique case.
@sjames1958gm is this a() common in javascript? I mean is it used frequently as u said its a unique case.
@challenger11 Passing functions as arguments is used a lot in javascript for example
arrays sort, map, reduce, forEach, every, some all take a function as a parameter.
My point was calling a() like this is only when a is a function.
arrays sort, map, reduce, forEach, every, some all take a function as a parameter.
My point was calling a() like this is only when a is a function.
@sjames1958gm can you help me with a little thing, i was trying to get div offset inside componentDidMount function using refs in the div, but i can't use it in constructor because it is called on the first render, how could i then get the divs ref from render(), and then pass it into another component ?
@sjames1958gm well, so if this function had a name and its not anonymous, will it still take (a) as a function??
@challenger11 the name of the function outside doesn't matter when passed into the function.
@challenger11 Just like you pass any other value, in js you can even pass functions, so the parameter takes the value of the function or the definition. If you want to use that function inside you refer to it by the name of the parameter.
@sjames1958gm lets say,
function someThing (a) {
console.log (a);
a();
}will it still be like this?
@gadzet I believe only in componentDidMount can you get the actual rendered layout including offsets.
I guess you could update the state with the offsets and use them in the next render pass. Interesting problem.
I guess you could update the state with the offsets and use them in the next render pass. Interesting problem.
@challenger11 you can only call
a(); if the passed value is a function.
@challenger11 Assuming you do something like:
someThing(function() { })'Or
function x() {
}
someThing(x);In both cases the function will still do a()
Profile Lookup :confused: :gun: please help wtf is going on?
var contacts = [
{
"firstName": "Akira",
"lastName": "Laine",
"number": "0543236543",
"likes": ["Pizza", "Coding", "Brownie Points"]
},
{
"firstName": "Harry",
"lastName": "Potter",
"number": "0994372684",
"likes": ["Hogwarts", "Magic", "Hagrid"]
},
{
"firstName": "Sherlock",
"lastName": "Holmes",
"number": "0487345643",
"likes": ["Intriguing Cases", "Violin"]
},
{
"firstName": "Kristian",
"lastName": "Vos",
"number": "unknown",
"likes": ["Javascript", "Gaming", "Foxes"]
}
];
function lookUpProfile(firstName, prop){
// Only change code below this line
for(i=0;i<contacts.length;i++){
if (firstName==contacts[i].firstName){
return contacts[i].firstName;
}else return "No such contact";
if (prop==contact[i].hasOwnProperty(prop)){
return contacts[i].prop;
}else return "No such property";
}
// Only change code above this line
}
// Change these values to test your function
lookUpProfile("Akira", "likes");
@sjames1958gm I was able to set the state but since it state is async function i was only able to get the state with the callback function in the componentDidMount, could therefore not pass the value inside the render
@saifsmailbox98 @sjames1958gm thanks guys, I need to dig little bit more into this??
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@munkhmanlai You are returning
firstName or"No such contact", by checking the first contact object only.
@gadzet If you update the state, then that value should be available the next time render is called (which I would think is immediately
@munkhmanlai Also, no need to return the
firstName
@munkhmanlai make sure you use contacts every time.
hasOwnProperty returns true/false - why compare to property name in prop
You are supposed to check hasOwnProperty only when firstName matches then if it exits return the value of the property
hasOwnProperty returns true/false - why compare to property name in prop
You are supposed to check hasOwnProperty only when firstName matches then if it exits return the value of the property
prop
@munkhmanlai
it is contacts too
prop==contact[i].hasOwnProperty(prop) will be false always for that arrayit is contacts too
*exist
@sjames1958gm ok so am i using .hasOwnProperty on firstName, not on the prop
@munkhmanlai no, use it on prop - then if true return prop
@sjames1958gm i thought that is what i did
does anyone can reference "Profile Lookup"in basic java script answer to me ?
@munkhmanlai if you need to check for more than one condition inside an if , you can use logical AND operator, like
if(x==1 && y==2) { //do something}
can I reference answer of "Profile Lookup"in basic javascript from you?
too hard
@munkhmanlai
var myObj = {
"x": 50,
"y": 40
}myObj.hasOwnProperty("x"); //true
myObj.hasOwnProperty("y"); //true
myObj.hasOwnProperty("z"); //false
console.log(str2); 是输出str2的值吧？在哪能看到来的？
@saifsmailbox98 what is this sorcery?
@saifsmailbox98 @saifsmailbox98 right, i understand what u wrote but can u show me if it is true, then return or do something
@saifsmailbox98 that part where if it true, then return something that part confuses me
@munkhmanlai You have seen how to do that earlier
@saifsmailbox98 do u get what i am saying or no?
@Chrono79 did i?
In Testing Objects for properties
yes
@Chrono79 damn
@munkhmanlai check if its hasOwnProperty returns true then return the property.
@dxd1108 in the developer console. https://www.freecodecamp.org/videos/console-and-logging
@sjames1958gm was able to solve it by setting initial value of state to 0 and checking if the state is more than that
@gadzet :+1:
@sjames1958gm thanks
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But is it possible to send the state value to components that are not children
?
@gadzet There are ways, for example the parent can pass a function that the child calls to pass the value up the hierarchy.j
hmm ok, but i see that you have to have a handling event to do this like onClick, is there something like onRenderSecondTime ? :D :D
probably not but you get what i mean
Hi all , I want to ask a question on reduce... Suppose I wanted to use only 2 of the four parameters, namely currentvalue and index. Could I do this without specifying the other ones in my function? And if yes, how will JS see which of the four parameters I intend to use?
Example
Example
array.reduce(function(currentval, index) {
}
@WAINGOR again, the second argument isn't index
check MDN docs
@Chrono79 please read my question :)
you can't
this example is hypothetical
allright, thanks @Chrono79
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:+1:
maybe map is more suited to do what you want
@Chrono79 are you saying that in this case I use code like this? Even though I will not use the 2nd parameter?
array.reduce(function(accum, currentval, currentindex) {
}
what are you trying to do, let's start with that
I am not aiming for a specific goal here... I just want to get my knowledge right
yes, you have to define them, even if you don't use them
unless you only want ot use the first 2
//初始化变量
var contacts = [
{
"firstName": "Akira",
"lastName": "Laine",
"number": "0543236543",
"likes": ["Pizza", "Coding", "Brownie Points"]
},
{
"firstName": "Harry",
"lastName": "Potter",
"number": "0994372684",
"likes": ["Hogwarts", "Magic", "Hagrid"]
},
{
"firstName": "Sherlock",
"lastName": "Holmes",
"number": "0487345643",
"likes": ["Intriguing Cases", "Violin"]
},
{
"firstName": "Kristian",
"lastName": "Vos",
"number": "unknown",
"likes": ["Javascript", "Gaming", "Foxes"]
}
];
function lookUp(firstName, prop){
// 请把你的代码写在这条注释以下
while(contacts.hasOwnProperty(firstName)){
return contacts[firstName];
}return "No such contact";
while(contacts.hasOwnProperty(prop)){
return contacts[prop];
}return "No such property";// 请把你的代码写在这条注释以上
}
// 你可以修改这一行来测试你的代码
lookUp("Akira", "likes");
you can skip the next 2 in that case, but if you want to use the first and the third one, you have to define the second, you can't skip it @WAINGOR
im going crazy
@2895388807 contacts is an array, it hasn't those properties
use only one loop to run through it
use a for loop instead
ok i try thx man
:confused: :gun:
@WAINGOR hey, I wonder if pasing in "" or None will work?
I am doing this problem https://projecteuler.net/problem=12 and I made a function on how many divisors a number have like 28 have 1,2,4,7,14,28.
function divs(n) { //28 => 6
let arr = [1];
for (let i = 2; i <= n/2; i++) {
if (n % i === 0) {
arr.push(i);
}
}
arr.push(n);
return arr.length;
}The problem is that my function is not fast enough. I found this function
function divs(n) {
let nod = 0;
let sqrt = Math.sqrt(n);
for (let i = 1; i <= sqrt; i++) {
if (n % i === 0) {
nod += 2;
}
}
if (sqrt * sqrt === n) {
nod--;
}
return nod;
}I dont understand why it uses sqrt(n) and nod += 2. Can someone help me understand this?
@hypercuber all numbers above sqrt(n) can't divide n exactly
Hello! My string should include only numbers or brackets or dashes or spaces. Can you help me with RegExp?
var reg = /[\s\d)(-]/;I want to use test() function for every character of my string but I can't declare RegExp correctly
@hypercuber Not fast enough ? You do know that the JS engines would run ur function millions of times if it wanted to ? Making micro perf optimizations is pointless and should only be done on workload heavy things like 3D games or big big databases
@GeorgeII brackets have a special menaing in regex, you should probably escape them, parentheses too
@Stuhl maybe the tests for that problem time out
What is the value of the first triangle number to have over five hundred divisors?
@GeorgeII
/[\s\d\(\)\-\[\]]/g
@Chrono79 Thanks. @Stuhl Well, my divs() function runs okay but all my code to work on that problem in project euler is not fast
function nthLayer(n) {
return .5 * n * (n + 1);
}
// function divs(n) { //28 => 6
// let arr = [1];
// for (let i = 2; i <= n/2; i++) {
// if (n % i === 0) {
// arr.push(i);
// }
// }
// arr.push(n);
// return arr.length;
// }
function divs(n) {
let nod = 0;
let sqrt = Math.sqrt(n);
for (let i = 1; i <= sqrt; i++) {
if (n % i === 0) {
nod += 2;
}
}
if (sqrt * sqrt === n) {
nod--;
}
return nod;
}
function divsNeeded(m) {
let n = 1
while (divs(nthLayer(n)) < m) {
n++;
}
return nthLayer(n);
}console.log(divsNeeded(501));
I need to use another method. I can get some hits here: http://www.mathblog.dk/triangle-number-with-more-than-500-divisors/
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@hypercuber why are you starting with n = 1 in divsNeeded?
you should improve that part
can anyone explain difference between one way data binding vs two way data binding
@shivamg11000 In what context, template to controller or between two components?
@SweetCodingInc in comparision to angular vs react
model view controller
@shivamg11000 : Conceptually there is none
in React as well, you have two way and one way binding
if you update something in template, it reflects in your component controller
whats the meaning of one way an two way data binding
(in case of react, it's not called
controller it's just component)
@shivamg11000 oneway data binding is when data flows in one way, two way data binding is when data flows in two ways. In context to MVC, One way binding means that the scope variable in the html will be set to the first value its model is bound to (i.e. assigned to) i.e. Model to View. Two way binding means that the scope variable will change it’s value every time its model is assigned to a different value i.e. Model to View and View to Model.
after scope nothing understood
data cannot be passed in siblings directly in readct
react*
Let;s assume you have nested components like
<list>
<list-child from-parent="listItem"></list-child>
</list>If you enable one way binding for list-child no matter what you do with listItem in list-child component, the reference of it in list will not be affected
that is one way binding
I dont't know angular
if you allow your
list-child to update listItem which is referred to as fromParent in your list-child component, whatever changes you make to fromParent will reflect in listItem of list component
concept is same for both angular and react
@alpox
@shivamg11000 sry :D clicked enter too early
@shivamg11000
one-way-binding: component will be updated with data as soon as there is new data. If you type something in the component(input) your data will not update.two-way-binding: component will be updated with data as soon as there is new data. If you type something in the component (input) your data will be updated with the input data.
any react lifecycle experts here ?
newbiew @gadzet
@gadzet Shoot
@shivamg11000
one-way means your data goes only one way - to the element but not back
the problem is that i am getting the offset of the div in the second render and passing it to the parent
@alpox whats react
one way or two way
in constructor i initialize the value which calls the function
@shivamg11000 one-way only
but it only returns the first value
from the first render
@shivamg11000 There is a context to one way or two way. Template to component is always 2 way
component to component can be either one way or two way
@SweetCodingInc In react there is no two-way
@SweetCodingInc whats Template in MVC
in case of react, even component to component is always one way
@SweetCodingInc Nope
@shivamg11000 template is V
@shivamg11000 tempalate = view
but every component is a view
@SweetCodingInc did you check out my problem ?
@SweetCodingInc In react is NO two-way. At all. Thats one of their selling points ;-)
@gadzet do you have codepen where I can see this problem?
ill make
@alpox okay you win
React will take lot time to expertisr
parent can pass data to child but child cannot pass data to parent only trigger change in the parent
@Chrono79 ty. Gonna try it
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@gadzet sure
@GeorgeII that regex is very basic, if you need your brackets and parentheses in the right order, you'll have to use a more complex one
@shivamg11000 on the contrary, react is pretty fast to get started with (as compared to Angular (2+))
@SweetCodingInc yes
that is exactly why you see too many mediocre devs flaunting react and writing bad code
@SweetCodingInc until someone sees lifecycles
when they really run into scenario where the seeming two way binding doesn't seem to work....
for example complex nested component hierarchy
but theres no two way data binding
redux can help here
@Chrono79 Instead of one what should I start with? Also I am trying to change my code to have Math.sqrt(n). I gotta go soon so I will do it when I come back. It should look like this:
function nthLayer(n) {
return .5 * n * (n + 1);
}
function divs(n) { //28 => 6
let arr = [1];
for (let i = 2; i <= Math.sqrt(n); i++) { //what if it is perfect sq ***
if (n % i === 0) {
arr.push(i);
}
}
arr.push(n);
return arr.length;
}
// function divs(n) { //yt || ask why this work ***
// let nod = 0;
// let sqrt = Math.sqrt(n);
// for (let i = 1; i <= sqrt; i++) {
// if (n % i === 0) {
// nod += 2;
// }
// }
// if (sqrt * sqrt === n) {
// nod--;
// }
// return nod;
// }
function divsNeeded(m) {
let n = 1;
while (divs(nthLayer(n)) < m) {
n++;
}
return nthLayer(n);
}
console.log(divsNeeded(501));
@shivamg11000 : That is why I am saying over and over again. There is a context to the argument whether there is two way binding in react or not.
Within component, it's always bound two way
between component, it's not (in react)
Nothing is bound two-way
In react
Just to say it again
In Angular one way or two way is design choice
Yes in angular
In angular you can easily specify it
@SweetCodingInc https://codesandbox.io/s/3lKkAGpJ4
@gadzet looking into it
@SweetCodingInc within component ,its always bound two way makes no sense
React is just one-way by design @SweetCodingInc react doesn't look at any changes on the DOM itself
as you see when i console log it in the function zero is only comming the second time
but if you console.log(this.data) in the render it will be undefined
@SweetCodingInc thanks in advance
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CBot
you called?
yes
@hypercuber - this may be farfetched, but looks like using sqrt cuts the number of iterations almost a 1/4 of n, which is almost .5 of n/2 ....so one would have to aggregate by 2 at each iteration to approximate the total where n%i===0
...your function has 13 iterations where the other has 5. You are also using an array and then function calls to store and add. See what happens when you get rid of the array and just count the number where n%i===0 and then add the given 2 at the end. ( from your original entry )
...your function has 13 iterations where the other has 5. You are also using an array and then function calls to store and add. See what happens when you get rid of the array and just count the number where n%i===0 and then add the given 2 at the end. ( from your original entry )
@gadzet how do I rerun your code?
@SweetCodingInc what do you mean ?
its automatic
@r-igle ThanksI saved your comment in atom I gotta go to work
@gadzet Dont use
this.data - use the state instead. Also, if you want to pass down a function which references its own context, you should bind it to the component in the constructor like:this.getLineOffset = this.getLineOffset.bind(this);
@gadzet Otherwise the
this in your function refers to the child component (The calling component) which would be Timeline. Timeline has no variable data defined.
@alpox I cant set state in the function since state is async
@alpox it actually worked with bind
@alpox thanks alot!!
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@gadzet so it will only render when the state is set right ?
@alpox
calling setState makes the component re-render
@gadzet :Sorry.. been away for a bit...
Yes . So I checked your code.. what is your expected behavior again?
i need to set the val
from
the getLineOffset
and reuse it
in render
@gadzet I see.. in your original, you had this
this.getLineOffset = this.getLineOffset();
thanks anyway @SweetCodingInc
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you're calling that function without a parameter, so that was returning
Second, your value of this was wrong
undefined.Second, your value of this was wrong
because when you call it from TimeLine component, this will refer to timeline component
you need to explicitly bind it to Home component like
this.getLineOffset = this.getLineOffset.bind(this);
yup
which makes sure you're not calling
getLineOffset at that line
and your proper context is set
great!
:+1:
how do i check this scope thing
if something is not set
should i just log this
yeah
to see if I'm in the right scope ?
log and see what is the the value of
this
right
@SweetCodingInc thanks
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react is much harder than angular or vue
its like a love and hate relationship
:D
@gadzet same question
It's not harder, it just assumes you understand scopes well
the moment scope hits the fan, most react devs just go hide in the jungle
the thing with the render funcion makes it a bit hard
so much for easier to learn lol
@gadzet : It's just a workflow specific to react, if you know the sequence, you won't fact such problems
i feel that using componentDidMount on the second render
is not a good practice
because it is undefined the first time
but i could not came with any other way to get element from the dom
to get offset
implement componentDidUpdate in that case
@gadzet mount lifecycles are for the first render as I know
because you won't be mounting component on update. (unless you do something as horrible as setState from where it shouldn't be done)
in that you will receive componentDidUpdate
Will -> before render()
Did -> after render()
Did -> after render()
but do you see any other way of getting an offset of the div which is rendered
@gadzet what u wanna do..?
pass parent values to child component ??
pass parent values to child component ??
i did it already @moigithub but i feel that I am not followin design pattern
you can see that the child element is getting the offset after the render
when to learn flux pattern
after redux or before
after redux or before
?
DidMount is after render
soo ur code is working correctly
like @shivamg11000 said
u cant extract elements info/properties if they are not "rendered" in the DOM (like offset)
soo ur code is working correctly
like @shivamg11000 said
u cant extract elements info/properties if they are not "rendered" in the DOM (like offset)
Hey all, working on my javascript calculator and running into some problems I can't seem to figure out.
I tried using eval() and I tried not using eval() and both versions are working fine when working with single digits (i.e. 6 + 9) but neither works with two digit numbers (i.e. 11 +13) - here's the pen to the one I'd like to make work - https://codepen.io/derekbmcintire/pen/XgPRRz?editors=1011
export default class Timeline extends Component {
componentWillMount(){
console.dir("willMount",this.refs.el);
}
componentDidMount() {
console.dir("didMount",this.refs.el)
this.props.sendData(this.refs.el.offsetLeft);
}
render() {
return <div className="timeline__container--line" ref="el" />;
}
}
if anyone can point me in the direction of what I am missing I would appreciate it!
so this is not a bad pratice ?
didmount only gets executed once
first time the page loads
first time the page loads
and the version with eval() - which is probably closer to actually working - https://codepen.io/derekbmcintire/pen/eRPZjE?editors=0001
@moigithub ok thanks again
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@derekbmcintire You need to add validations
to your calculator first
@derekbmcintire like make sure the input is clear of extra decimal points, or invalid values.
@derekbmcintire then you can easily run eval on it
@derekbmcintire https://codepen.io/abhinavthinktank/pen/BZwBVy
Hello everyone please help
@derekbmcintire something like
@derekbmcintire
Make sure input can be evaluated
@derekbmcintire
Evaluate input expression on click of "="
function myLocalScope() {
var myVar =5;
console.log(myVar);
}
myLocalScope();
console.log(myVar);
help to correct
@derekbmcintire USE innerText instead of innerHTML
if u console.log(input) u will see it have extra characters (newline)
soo when u enter 78+3
internally is
which evaluates to NaN
if u console.log(input) u will see it have extra characters (newline)
soo when u enter 78+3
internally is
Number(7(newline)8) + Number(3 )which evaluates to NaN
no language or framework is harder or easier
it all depends on the programmer
imo
unless you are comparing Cobol to JS that is :P
assembly language :)
@Sros-Chourb if i recall.. there are also comments on the original code
which serves as hint/instructions
which serves as hint/instructions
@moigithub ahh... I was having trouble getting that to show up in the console.log with the onclick - at least I see what is happening now!
@moigithub thanks!
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@WAINGOR No language or framework is harder or easier, except when it is. :p
@kumquatfelafel all is nothing
@WAINGOR Yes is cheese.
...
No is also cheese.
No is also cheese.
@Sros-Chourb There is an instruction on what to do in the comments I believe. iirc, you have to delete a line.
@Sros-Chourb They just want you to see that outside of myLocalScope's "scope", the "local" variable myVar is not visible/value can't be used (not without return anyway)
I'm having a problem with challenge Seek and Destroy
here is my code
function destroyer(arr) {
var finalArr=[];
var itemsLeft=arr[0].length;
for(var items=0;items<=itemsLeft;items++){
for(var numSearch=arr.slice(1).length;numSearch>1;numSearch--){
var isAMatch=arr.match(arr[numSearch-1] /g);
if(isAMatch){break;}else{
finalArr.push(arr[items]);
break;
}
}}
return finalArr;
}
destroyer([1, 2, 3, 1, 2, 3], 2, 3);
@williamtech814 destroyer function is called with 3 values (an array and 2 numbers)
[1, 2, 3, 1, 2, 3],
2,
3
ur function have 1
that arr refer to
soo arr[0] is 1
to access the extra values (2, 3) u need to use the
..reading the helpful links on the instruction should help
[1, 2, 3, 1, 2, 3],
2,
3
ur function have 1
named parameter arrthat arr refer to
[1, 2, 3, 1, 2, 3]soo arr[0] is 1
to access the extra values (2, 3) u need to use the
arguments object..reading the helpful links on the instruction should help
Ahhh, makes sense. I thought it was all like an array of sorts
@moigithub thanks
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why doesn't scroll event event firing ? https://codesandbox.io/s/v22xP1J6m
var first = function(n) {
return n[0];
}
console.log(first([7, 9, 0, -2],3));[7, 9, 0] instead. What maybe a problem?
@Hello911
What is the name of this sorta slide up tag where you press the little exposed arrow and the tag with content slide up? I dont know where to find a tutorial for this.
What is the name of this sorta slide up tag where you press the little exposed arrow and the tag with content slide up? I dont know where to find a tutorial for this.
@serhiicss return n[0]; returns the first element of array
@serhiicss Can you post the problem text? There are a few ways to return 7,9,0 based on that input, for example:
var first = function(n) {
return n.slice(0,arguments[1]);
}
console.log(first([7, 9, 0, -2],3));but it depends on expected input to the first function.
var first = function(n) {
return n.slice(0, 3);
}
console.log(first([7, 9, 0, -2]));
:)
- Write a JavaScript function to get the first element of an array. Passing a parameter 'n' will return the first 'n' elements of the array.
Test Data :
console.log(first([7, 9, 0, -2]));
console.log(first([],3));
console.log(first([7, 9, 0, -2],3));
console.log(first([7, 9, 0, -2],6));
console.log(first([7, 9, 0, -2],-3));
Expected Output :
7
[]
[7, 9, 0]
[7, 9, 0, -2]
[]
@serhiicss And your question is?
hi guys
how do i run this code again
function threeInOne(arr) {
var output = [], copy;
copy = arr.slice();
copy = copy.splice(0, 3);
copy = copy.reduce( function (a, b) {
return a + b
},0)
output.push(copy);
return output;
}
with a loop i mean
@kelechichinaka call the function again?
i dont get @JohnnyBizzel
@serhiicss I think you'd want something like:
var first = function(arr, n) {
return arr.splice(0, n || 1);
};
That should give a general idea though ^^
@kelechichinaka threeInOne(arr); threeInOne(arr); threeInOne(arr); // runs 3 times
Hey will anyone share their Simon Game project. It will be a great help... thank you
@ay2306 there is a lot of on github if you google the task name, it also has few hints before you have to copy the code
@gadzet I dont want to copy. I want an idea if it should be round only.. I am terrible at design so am trying to that round thing
can anyone tell me why these links arent getting back to the wiki pages?
$('#output').prepend("<li><a href='wikipedia.com/wiki/" + test[i].title + "'>" + test[i].title + "</a>" + test[i].snippet +"</li>");
is the arguments keyword a global variable?
can I use it in a function?
function destroyer(arr) {
var testNum=arguments.length-1;
var finalArr=arr.filter(
function(item){for(var i=1;i<=testNum;i++){
if(item==arguments[i]){return false;}}
return true;
});return finalArr;
}
destroyer([1, 2, 3, 1, 2, 3], 2, 3);
https://repl.it/JTPf/1 @williamtech814
@jasonrest URLs need to start with
https://
"<li><a href='https://en.wikipedia.org/wiki/"
@SkyC0der Im an idiot. I had .com and the https was missing. thanks
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ugggggghhhhhhh
lol, don't be so hard on yourself :)
you would think by now that our browser could tell us something more than "404" when a page isn't found
@williamtech814 you can, but it's advisable to convert the arguments into an array
@SkyC0der its just so annoying that i fully grasp the complex subjects but concatenation, double quotes etc always stop me from finishing a project.
@williamtech814 also, make sure you're looping through the arguments properly. That one doesn't work because 'i' starts at 1
oh nevermind lol yeah you want it to start at 1
@jasonrest if i look up freeCodeCamp in your Wikipedia Viewer, i get Prisoner-of-war camp lol
Somebody know why i can not get back the result in my location??
@John-freeCodeCamp ??? lol let me see
@John-freeCodeCamp that is scary. but but but, thats not because of my coding i don think. right. and if you put freecodecamp one word. it gets there. sort of
At teh end lol
@jasonrest look up "Meaning of Life" and teh third one down lol
i revised mi code , and the google api, i wanto to return the locatatión in the weather app, but i can not understand why my
$(#locate).html(province) dosent change my location in the html..... i tried outside the getJSON function and it works (but i dont hace the variables..., i can not get result inside getJSON ,even "text" ..... i can not change my locate text in html.... anyone can help me on this??
What is the difference between a type error and a reference error?
jasonrest
@jasonrest