How can i define a variable with a variable in javascript?

Question

EDIT 2 : This is my first post on stock overflow and although I sometimes have some bad, questions to ask. i thought id at least fix the formatting considering I can not delete this.

I essentially wanted to automate variable creation , although at the time I did not not such things as arrays existed surprisingly.

I want to automate the creation of this variable

var l = createSprite(200,200);

I want to be able to define one variable , with another like this :

var count = 5;
var l + count = 1;
count++;
var l + count = 2;

var l=30 
var l + "foo" = 40`

if I were to run this, lfoo would be returned undefined. Why? Is this impossible? If so how can i automate defining variables?

Why do you want that? You can create the new variable directly with `var lfoo = 40`. — 31piy, Jun 07 '18 at 07:08
you can't define variables like this. you have to define it through writing the absolute name for them. But to call them you can use window["l"+"foo"] — Ullas Hunka, Jun 07 '18 at 07:10
Possible duplicate of [Use dynamic variable names in JavaScript](https://stackoverflow.com/questions/5117127/use-dynamic-variable-names-in-javascript) — mypsi, Jun 07 '18 at 07:17

score 1 · Answer 1 · answered Jun 07 '18 at 07:09

1

You could take an object and use l as part of the key for the access.

var l = 30 ,
    object = { [l + "foo"]: 40 };

console.log(object[l + "foo"]);
console.log(object);

answered Jun 07 '18 at 07:09

Nina Scholz

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score 1 · Answer 2 · answered Jun 07 '18 at 07:17

1

You can't define variables like this. You have to define it through writing the absolute name for them. But to call them you can use window["l"+"foo"].

var l = 40;
var lfoo = 30;
console.log(window["l"]+"...."+window["l"+"foo"]);

answered Jun 07 '18 at 07:17

Ullas Hunka

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score 1 · Answer 3 · answered Jun 07 '18 at 07:17

1

You could use window to declare global variables

var str = 'l' + 'foo';
window[str] = 40;
//Then you can access lfoo directly

answered Jun 07 '18 at 07:17

Charlie

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How can i define a variable with a variable in javascript?

3 Answers3