FreeCodeCamp/HelpJavaScript

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.

Joseph

@revisualize

because it isn't an array.

@jdc101214 also, your function is returning undefined

Jason Luboff

@JLuboff

Also....your filter isn't doing anything

Joseph

@revisualize

That too.

Pieter Stokkink

@forkerino

and .filter() requires a function as an argument that returns true or false

Joseph

@revisualize

.filter() needs a function.

Yeah that.

[true, true, false, false, true, false, false, true, true].filter(function (x) { return x });
[23,1,6,12,17,3,2,5,19,86,87].filter(function (x) { return x % 2 === 0 });

function someArguments (name) {
     console.log(name);
     console.log(arguments);
     return "Hello " + name;
}
someArguments("Joseph", "is", "an", "awesome", "guy", "so", "he", "thinks");

Jean Marco Romero

@volkranium

Supp fellow coders????

somebody here feel like all the JS you know is basically syntax?

kish21

@kish21

Zaluth

@Zaluth

in the seek and destroy challenge, my code returns an empty array, why?

function destroyer(arr) {
  var args = [].slice.call(arguments);
  var slice = args.slice(1);
  var join = slice.join(", ");

  // slice = [2,3]
  // arr = [1, 2, 3, 1, 2, 3]
  // args = [[1, 2, 3, 1, 2, 3], 2, 3]

  function filter(value) {
    return value === join;
  }

  var seek = arr.filter(filter);
  return seek;

}

destroyer([1, 2, 3, 1, 2, 3], 2, 3);

Gilbert

@GilTorch

Stuck at : https://www.freecodecamp.com/challenges/mutations

Moisés Man

@moigithub

@Zaluth what value do u think.. ur join variable have ?
if u call ur function like this destroyer([1, 2, 3, 1, 2, 3], 2, 3);

@GilTorch do u have any code ?

David Amanze

@GodKingShogun

@MessiaHack you still here

Zaluth

@Zaluth

@moigithub join is "2, 3"

Moisés Man

@moigithub

yep.. and do u know HOW filter uses the callback ? @Zaluth

David Amanze

@GodKingShogun

since @MessiaHack isn't here anymore, can someone take a look at my code and see what i did wrong. by the way the challenge wants me to find the longest word in a string

function findLongestWord(str) {
  return str.split(" ").reduce(function(a,b) {
    a.length > b.length ? a.length:b.length;
});
}

Zaluth

@Zaluth

@moigithub it returns an array with the condition in the function

Moisés Man

@moigithub

@GodKingShogun reduce callback need u to RETURN some value.. whatever value u return will be the next value for a variable on next iteration

Stephen James

@sjames1958gm

@GodKingShogun Missing the return value in the "callback"

HeebieGeeBee

@HeebieGeeBee

i think loops are finally really starting to click

Moisés Man

@moigithub

@Zaluth filter have a internal loop
it picks ECH value of the array u apply filter on... and pass it as argument to ur callback function
sooo

[1,2,3,4,5].filter( function (num) {
   console.log(num);
})

will output
1
2
3
4
5

Stephen James

@sjames1958gm

@HeebieGeeBee :+1:

@Zaluth use slice (array) and indexOf in your function

David Amanze

@GodKingShogun

@moigithub and @sjames1958gm i added the return but i am not yet done with the challenge yet. what else is wrong with my code

Stephen James

@sjames1958gm

@GodKingShogun what did you return?

Moisés Man

@moigithub

probably IF u only added the return... the next a value will be a number

Stephen James

@sjames1958gm

@GodKingShogun So your first a is a string - but your subsequent a values are numbers so you have an issue there

@moigithub :+1:

Moisés Man

@moigithub

:D @sjames1958gm

David Amanze

@GodKingShogun


function findLongestWord(str) {
  return str.split(" ").reduce(function(a,b) {
    return a.length > b.length ? a.length:b.length;
});
}

Moisés Man

@moigithub

and numbers do NOT have .length property

Stephen James

@sjames1958gm

@GodKingShogun there are a couple of ways to solve = always make your prev value a number (you have to have initial value of 0)
always make your prev value a string (add a length at the end of your reduce.

Long Phan

@longp

Is anyone able to help me with fileReading question, im trying to parse through a text file

Moisés Man

@moigithub

@Zaluth soooo applying that above example to ur code.. internally its doing

function filter(value) {
    return value === join;
  }

 [1, 2, 3, 1, 2, 3].filter(filter);

return 1 === "2, 3"
return 2 === "2, 3"
etc.. on each iteration
and since that comparation return false.. it filter everything out returning a empty array

David Amanze

@GodKingShogun

@sjames1958gm i did both those things and i am still coming up short

Stephen James

@sjames1958gm

@GodKingShogun Well only one would be needed - let me see

David Amanze

@GodKingShogun


function findLongestWord(str) {
  return str.split(" ").reduce(function(a,b) {
    return a.length > b.length ? a.length:b.length;
}).length;
}

Stephen James

@sjames1958gm

@GodKingShogun so you need to return a : b (so that previous remains a string) so that the last length makes sense

David Amanze

@GodKingShogun

@sjames1958gm so just add a return in front of the a.length part

Aaron

@aaronedwarda

whats up good people!

Stephen James

@sjames1958gm

function findLongestWord(str) {
  return str.split(" ").reduce(function(a,b) {
    return a.length > b.length ? a : b;
}).length;
}

@GodKingShogun By returning the string value the next time a.length makes sense

Aaron

@aaronedwarda

@sjames1958gm checkout out code newbie and javascript jabber today at work, both good! thanks

CamperBot

@camperbot

aaronedwarda sends brownie points to @sjames1958gm :sparkles: :thumbsup: :sparkles:

:star2: 4929 | @sjames1958gm |http://www.freecodecamp.com/sjames1958gm

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