在JavaScript阵列交换两个项目 [英] Swapping two items in a javascript array

问题描述

可能重复：结果
  的Javascript交换数组元素

我有一个这样的数组：

this.myArray = [0,1,2,3,4,5,6,7,8,9];

现在我想要做的是，两个项目交换位置给自己的立场。
例如，我要与第8项（也就是7）交换项目4（也就是3）
这将导致：

Now what I want to do is, swap positions of two items give their positions. For example, i want to swap item 4 (which is 3) with item 8 (which is 7) Which should result in:

this.myArray = [0,1,2,7,4,5,6,3,8,9];

我怎样才能做到这一点？

How can I achieve this?

推荐答案

只是重新分配的元素，创造了一个中间变量保存第一个在你写：

Just reassign the elements, creating an intermediate variable to save the first one you over-write:

var swapArrayElements = function(arr, indexA, indexB) {
  var temp = arr[indexA];
  arr[indexA] = arr[indexB];
  arr[indexB] = temp;
};
// You would use this like: swapArrayElements(myArray, 3, 7);

如果你想使这个更容易使用，你甚至可以将其添加到内置阵列原型（如肯纳贝克@建议）;但是，要知道，这通常是一个坏的模式，以避免（因为这可以创建问题，当多个不同的图书馆有在内建类型属于什么不同的想法）：

If you want to make this easier to use, you can even add this to the builtin Array prototype (as kennebec@ suggests); however, be aware that this is generally a bad pattern to avoid (since this can create issues when multiple different libraries have different ideas of what belongs in the builtin types):

Array.prototype.swap = function(indexA, indexB) {
   swapArrayElements(this, indexA, indexB);
};
// You would use this like myArray.swap(3, 7);

请注意，该溶液显著比使用替代剪接更有效（）。 （O（1）VS为O（n））。

Note that this solution is significantly more efficient than the alternative using splice(). (O(1) vs O(n)).

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