Javascript: Naming arrays programmatically

Question

Is it possible to create a new Array, giving it the name of the content of a variable?

For example something like this:

var nameofarray = "array_name";
var ¿nameofarray? = new Array();

So that ¿nameofarray? gets the value of "array_name"?

http://stackoverflow.com/questions/5117127/javascript-dynamic-variable-name — musicnothing, Jun 21 '13 at 22:36
`this` will always refer to the object that a function is a method of, whatever that is, unless a different scope is set with `apply()`, `call()` etc. It doesn't really matter what `this` is, as long as we know it's available in the current scope and it's an object, we can use it, but yes, it could cause some strange behaviour if we don't keep close track of what `this` really is, or try accessing it in lower scopes, like we would with variables declared in higher scopes etc. — adeneo, Jun 21 '13 at 23:09
I'm not sure why I want to do that. I'm having problems with an asynchronous call, so that the second call overrides the Array before the first call writes the output. So I want to have two arrays, and I thought giving different names to the arrays would be a good idea. Excuse me if I'm wrong. — gines capote, Jun 21 '13 at 23:41

Andreas Louv · Answer 1 · 2013-06-21T22:42:10.483

4

Assuming you are in global scope (called window) so:

var nameofarray = "array_name";
window[nameofarray] = new Array();

Otherwise it's only posible on objects:

function a() {
    var nameofarray = "array_name";
    var obj = {};
    obj[nameofarray] = new Array(); 
}

You can also use eval. Which is used for evaluating a string to JavaScript code:

eval('var '+ nameofarray+'=new Array()');

This will work in local scopes as well, but I hardly ever recorment it to anyone.

edited Jun 21 '13 at 22:42

answered Jun 21 '13 at 22:35

Andreas Louv

2

For the love of polar bears, why would you assume global scope? The use of globals should be minimized. The assumption is therefore that the variables are local. – Šime Vidas Jun 21 '13 at 22:36
I'm guessing they wouldn't, but that's the only way to do it. – musicnothing Jun 21 '13 at 22:36
2

@ŠimeVidas Because OP doesn't specify any more details, but that said I would agree with you. – Andreas Louv Jun 21 '13 at 22:37
@NULL In my book, bad practices shouldn't be assumed. – Šime Vidas Jun 21 '13 at 22:38
@ginescapote You are welcome, remember that you can accept answer, can see on your profile that you haven't accepted any yet. – Andreas Louv Jun 21 '13 at 23:37
Thanks @NULL I hope accepting answers is clicking on the up arrow, I've done it now. – gines capote Jun 22 '13 at 11:41
@ginescapote You have to click the tick below the arrows :) http://roi.webfactional.com/img/so/so_tick.png – Andreas Louv Jun 22 '13 at 16:35

score 1 · Answer 2 · edited May 23 '17 at 11:56

1

edited May 23 '17 at 11:56

Community

answered Jun 21 '13 at 22:35

Chad Seibert

score 1 · Answer 3 · answered Jun 21 '13 at 22:35

1

If nameofarray is declared in the global scope, you can use the window object:

window[nameofarray] = [];  // Use an array literal instead also
^^^^^^^^^^^^^^^^^^^

But you really shouldn't be doing this.

answered Jun 21 '13 at 22:35

David G

3 Answers3