Pushing numbers into an array

Question

Trying to do something simple, but not sure what I am doing wrong.

I simply want to call a function with number arguments and push those numbers into a new array...

function someFunction(n){
  var newArray = new Array(n);
  for(var i=0; i < n.length; i++){
    newArray += n[i];
  }
  return newArray;
}

console.log(someFunction(3,5,4,5));

Here is bin

http://stackoverflow.com/questions/2141520/javascript-variable-number-of-arguments-to-function take a look at this - here is explained how to deal with a variable number of arguments, which is, if I understand good, your main issue. And also at this http://www.w3schools.com/jsref/jsref_push.asp - here is how to push elements to a javascript array. — Rafael Korbas, Feb 01 '16 at 21:29
Start with MDN; you have a problem on nearly every line here. — Evan Davis, Feb 01 '16 at 21:29

gfrobenius · Accepted Answer · 2016-02-01T22:00:59.130

3

This will get those numbers into the array for you. And it will do it for unlimited numbers supplied: https://jsfiddle.net/a9umss9a/3/

function someFunction(){
  var newArray = [];
  for(var i=0; i < arguments.length; i++){
    newArray.push(arguments[i]);
  }
  return newArray;
}

console.log(someFunction(3,5,4,5));

console.log(someFunction(3,5,4,5,100,200,300,400,500));

edited Feb 01 '16 at 22:00

answered Feb 01 '16 at 21:32

gfrobenius

3,987
8
34
66

Thanks gfrobenius, that is what I was looking for. – Lucky500 Feb 01 '16 at 21:35
Why have a named arg `n` if you're not using it? Why use the `Array` constructor instead of `var newArray = []`? – Evan Davis Feb 01 '16 at 21:55
Don't have to. Just using the OP code to get what he wanted. I made the changes tho, thanks @Mathletics – gfrobenius Feb 01 '16 at 21:59

score 2 · Answer 2 · answered Feb 01 '16 at 21:54

You can do this as a one-liner:

function toArray() {
    return [].slice.call(arguments);
}

Here's the breakdown of issues in your code.

function someFunction(n){ // this captures the FIRST argument as n
  var newArray = new Array(n); // this creates a new Array of length n (in your case, 3, which is not accurate
  for(var i=0; i < n.length; i++){ // n is a number and has no length property
    newArray += n[i]; // newArray is an array, so you must push to it; the + operator makes no sense
  }
  return newArray;
}

You see, sometimes sarcasm does the trick. Thanks for the great detailed answer! — Lucky500, Feb 01 '16 at 22:05

score 0 · Answer 3 · answered Feb 01 '16 at 21:32

0

someFunction requires 1 input of type array, not 4 inputs:

function someFunction(n){
  var newArray = [];
  for(var i=0; i < n.length; i++){
    newArray.push(n[i]);
  }
  return newArray;
}

console.log(someFunction([3,5,4,5]));

answered Feb 01 '16 at 21:32

Jacob Petersen

1,463
1
9
17

True. But doing it this way makes the function pointless. You could just replace the guts of the function with `function someFunction(n){ return n; }` and get the same thing. The OP wanted this format: `someFunction(3,5,4,5)`. – gfrobenius Feb 01 '16 at 21:37

score 0 · Answer 4 · answered Feb 01 '16 at 21:56

0

A solution with direct building of an array.

function someFunction() {
    return Array.apply(null, arguments);
}

document.write('<pre>' + JSON.stringify(someFunction(3, 5, 4, 5), 0, 4) + '</pre>');

answered Feb 01 '16 at 21:56

Nina Scholz

376,160
25
347
392

Pushing numbers into an array

4 Answers4