[Asperant]

There are two variables:

var index1=5;
var index2=7;

And I need start working with one of them by next way:

someFunction(index."1"); //Or something like this

i.e. - catenation of variable name

My question:

Does such possibility exist in Javascript, or not? And what syntax? I've been looking for, but possibly it is not often usable possibility

[Atli]

You'd be much better of using an array or an object.

var indexes = [5, 7];
someFunction(index[0]);

// Or
var indexes = {
    1 : 5,
    2 : 7
}
someFunction(indexes[1]);

However, if you absolutely must use an actual variable name, you could, in some situations (like, if it's all happening in the global scope) access the variable as a property of this. You may have to resort to using eval() though, which is why I strongly recommend using an array or object.

[Asperant]

Atli, Thank You! The solution is eval()

[BobRodes]

No it isn't. An array is. Eval is bad.

[Asperant]

BobRodes, on 13 March 2012 - 02:42 PM, said:

No it isn't. An array is. Eval is bad.

I think - not in this case.
index1
index2
indexABC
indexLALALa, etc.

If to use numbers - ok, but if to use letters ?

[Atli]

Then you would move onto my second suggestion: objects. You can use either numbers or strings as property names, making it sort of like an associative array.

If you want a more "array"-like syntax for it than I used in my last example, you can also do this:

var indexes = {};

indexes[1] = 5;
indexes[2] = 9;
indexes["ABC"] = 15;

console.log(indexes[1]); // 5
console.log(indexes["ABC"]); // 15

Whatever you choose to do, just keep in mind that it's rarely a good idea to use eval. It's both insecure and relatively slow. If you can avoid using it (which appears to be the case here) then you should.