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"?
3 Answers
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.
You would maybe like to read: http://javascriptweblog.wordpress.com/2010/04/19/how-evil-is-eval/
7 Comments
Šime Vidas
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.
musicnothing
I'm guessing they wouldn't, but that's the only way to do it.
Andreas Louv
@ŠimeVidas Because OP doesn't specify any more details, but that said I would agree with you.
Šime Vidas
@NULL In my book, bad practices shouldn't be assumed.
Andreas Louv
@ginescapote You are welcome, remember that you can accept answer, can see on your profile that you haven't accepted any yet.
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In PHP and other languages, they are called variable variables. This might help: Javascript "Variable Variables": how to assign variable based on another variable?
Comments
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.
this[nameofarray] = new Array();thiswill always refer to the object that a function is a method of, whatever that is, unless a different scope is set withapply(),call()etc. It doesn't really matter whatthisis, 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 whatthisreally is, or try accessing it in lower scopes, like we would with variables declared in higher scopes etc.