How can i change the variable name in javascript?

Question

I have some js code like this:

var parameter0 = 12345;
var parameter1 = 54321;
var parameter2 = 33333;
var parameter3 = 99990;

function selectValue(number) {
alert(parameter+number);
}

selectValue(2);

Here is a fiddle - https://jsfiddle.net/frwd2qLg/

This code will not work, because, for example, for number = 2, it will not show 33333, but will be undefined. Any workaround?

This sound like an [x/y problem](https://meta.stackexchange.com/questions/66377/what-is-the-xy-problem). Why are you trying to do that? Consider using an array, with the index as the number input. — 0stone0, Jan 03 '22 at 15:40
Learn about the use of arrays: https://www.w3schools.com/js/js_arrays.asp — Elson Ramos, Jan 03 '22 at 15:40
`eval` is dangerous, but might be what you are looking for here (but it would be better to follow the other advice here) — Jonathan.Brink, Jan 03 '22 at 15:41
`var parameters = [12345, 54321, 33333, 99990]; console.log(parameters[number]);` — epascarello, Jan 03 '22 at 15:43
yes, i just converted this into one array and use parameters[i], thanks — Alex Fatun, Jan 03 '22 at 15:44

score 0 · Answer 1 · answered Jan 03 '22 at 15:44

As people said in your comments, you could use an array or an object to do this task. But answering your question you culd use an eval to access the variable name.

var parameter0 = 12345;
var parameter1 = 54321;
var parameter2 = 33333;
var parameter3 = 99990;

function selectValue(number) {
  alert(eval("parameter"+number));
}

selectValue(2);

How can i change the variable name in javascript?

1 Answers1