在JavaScript中使用递归展平嵌套数组 [英] Flatten nested arrays using recursion in JavaScript

问题描述

我试图在保留顺序的同时展平嵌套数组，例如 [[1,2]，3，[4，[[5]]]] 应转换为 [1,2,3,4 ，5] 。

I'm trying to flatten nested arrays while preserving the order, e.g. [[1, 2], 3, [4, [[5]]]] should be converted to [1, 2, 3, 4, 5].

我正在尝试使用递归来执行此操作，但下面的代码不起作用我不喜欢明白为什么。我知道还有其他方法可以做到，但我想知道这有什么问题。

I'm trying to use recursion in order to do so, but the code below does not work and I don't understand why. I know there are other methods to do it, but I'd like to know what's wrong with this.

function flatten (arr) {
  var newArr = [];
  for (var i = 0; i < arr.length; i++) {
    if (Array.isArray(arr[i])) {
      flatten(arr);
    } else {
      newArr.push(arr[i]);
    }
  }
  return newArr;
}

flatten([[1, 2], 3, [4, [[5]]]]);

谢谢

推荐答案

当递归调用 flatten 时，你需要将 arr [i] 传递给它，然后连续结果与newArr。所以替换这一行：

When calling flatten recursively, you need to pass arr[i] to it and then concat the result with newArr. So replace this line:

flatten(arr);

with：

newArr = newArr.concat(flatten(arr[i]));

这篇关于在JavaScript中使用递归展平嵌套数组的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！