How to declare variable names dynamically in java script?

Question

I have an array:

var arr = ['a', 'b', 'c'];

I need to declare within a for loop, variables value_x- when x is each one of the array value.

what I've tried:

var i;
for(i=0;i<3;i++){
    var x = 'hello there';
    var str = 'var ' + `value_${arr[i]}` + ' = ' + "'" + x + "'" + ';'
    eval(str);
}

now, str =

var value_a = 'hello there';

but the eval() call return this error:

error: EvalError: Dynamic code evaluation disallowed‏

now, I saw also solution which used window object, like:

window[`value_${arr[i]}`] = x;

and this also return error:

error: ReferenceError: window is not defined

which because this is local script, not on the server. please help.‏ ‏

‏

You don't need dynamically created variable names, use a proper data structure, an array or an object, instead. — Teemu, May 26 '21 at 15:43
no, I do need dynamically created variable names. in fact I have dozens of names I want to declare in same logic. — riki, May 26 '21 at 15:44
You cannot do that, so you need a Plan B. If you use an object, you can create property names dynamically. (Yes, you can create properties on the global object context, but that's asking for trouble.) — Pointy, May 26 '21 at 15:45
This seems like a bad solution to whatever your actual problem is. — Nikki9696, May 26 '21 at 15:46
@rikir — Whatever XY problem you have, dynamic variable names are the worst possible solution for it. Use an object. — Quentin, May 26 '21 at 15:46
JavaScript doesn't have a concept for dynamically created variable names like some other languages have, you've to rethink your logic. — Teemu, May 26 '21 at 15:46
@Quentin, thanks for you advice. can you please refer me to example for dinamically object properties names? — riki, May 26 '21 at 15:48
Your problem solving via dynamic variables is not a good solution. The wrong design always leads to a difficult solution. My recommendation is to use other data structures such as Array or Object. — Sokmesa Khiev, May 26 '21 at 15:50

0 Answers0