Access variable dynamically based on another variable value in JavaScript

Question

const var1 = "Some Value"
const var2 = "Another value"

const var3 = "var1"

Then how can we access the variable var1 by using var3? var3 has a value var1 and there's a variable exists with var1, so this should return "Some Value" instead of "var1"

Javascript doesn't have any good way for dynamic variable names — Maheer Ali, Feb 24 '21 at 08:17

Liftoff · Answer 1 · 2021-02-24T08:23:15.523

3

If you have the name of a variable as a string, you can access it by key on the window.

var var1 = "abc";
var var2 = "var1";

console.log(window[var2]);

In Node.js, you would use the global keyword instead.

console.log(global[var2]);

edited Feb 24 '21 at 08:23

answered Feb 24 '21 at 08:15

Liftoff

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That would only work in a browser (not in nodejs). Op doesn't say what the environment is other than javascript. – Allan Wind Feb 24 '21 at 08:17
Updated for node as well – Liftoff Feb 24 '21 at 08:20
Format tweak and you are golden (for consistency with the first example). – Allan Wind Feb 24 '21 at 08:20
This is only going to work if you are doing everything in global scope. Wrap everything inside a function and it will break – diwakersurya Feb 24 '21 at 08:27

score 2 · Accepted Answer · answered Feb 24 '21 at 08:16

2

You can use eval()

const var1 = "Some Value"
const var2 = "Another value"
const var3 = "var1"

console.log(eval(var3))

answered Feb 24 '21 at 08:16

axtck

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score -1 · Answer 3 · answered Feb 24 '21 at 08:22

It would be better if you create an object dynamically and try to access using bracket notation. you won't need var. It will work with let and const as well.

console.log({var1:var1,var2:var2,var3:var3}[var3])

In latest es you can also do something like

console.log({var1,var2,var3}[var3])

Access variable dynamically based on another variable value in JavaScript

3 Answers3