javascript - Variable amount of nested for loops

Question

Edit: I'm sorry, but I forgot to mention that I'll need the values of the counter variables. So making one loop isn't a solution I'm afraid.

I'm not sure if this is possible at all, but I would like to do the following. To a function, an array of numbers is passed. Each number is the upper limit of a for loop, for example, if the array is [2, 3, 5], the following code should be executed:

for(var a = 0; a < 2; a++) {
     for(var b = 0; b < 3; b++) {
          for(var c = 0; c < 5; c++) {
                doSomething([a, b, c]);
          }
     }
}

So the amount of nested for loops is equal to the length of the array. Would there be any way to make this work? I was thinking of creating a piece of code which adds each for loop to a string, and then evaluates it through eval. I've read however that eval should not be one's first choice as it can have dangerous results too.

What technique might be appropriate here?

Answer 1

Recursion can solve this problem neatly:

function callManyTimes(maxIndices, func) {
    doCallManyTimes(maxIndices, func, [], 0);
}

function doCallManyTimes(maxIndices, func, args, index) {
    if (maxIndices.length == 0) {
        func(args);
    } else {
        var rest = maxIndices.slice(1);
        for (args[index] = 0; args[index] < maxIndices[0]; ++args[index]) {
            doCallManyTimes(rest, func, args, index + 1);
        }
    }
}

Call it like this:

callManyTimes([2,3,5], doSomething);