可变数量的嵌套for循环 [英] Variable amount of nested for loops

问题描述

编辑：对不起，但我忘了提到我需要计数器变量的值。所以制作一个循环不是我害怕的解决方案。

我不确定这是否可行，但我想请执行下列操作。
对于函数，传递一个数字数组。每个数字都是for循环的上限，例如，如果数组是 [2,3,5] ，则应执行以下代码：

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]);
          }
     }
}

所以嵌套的数量是多少循环等于数组的长度。有没有办法让这项工作？我正在考虑创建一段代码，将每个for循环添加到一个字符串，然后通过 eval 进行评估。不过我读过 eval 不应该是首选，因为它也会产生危险的结果。

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.

什么技术可能适合这里？

What technique might be appropriate here?

推荐答案

递归可以很好地解决这个问题：

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);
        }
    }
}

这样称呼：

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

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