javascript中索引_数组：使用JavaScript在特定索引处插入项目

Dear 丶 2023-02-22 03:46 25阅读 0赞

javascript中索引

There are many tasks related to arrays that sound quite simple but (1) aren't and (2) aren't required of a developer very often. I was encountered with one such task recently: inserting an item into an existing array at a specific index. Sounds easy and common enough but it took some research to figure it out.

与数组相关的许多任务听起来很简单，但开发人员通常不需要(1)，也不需要(2)。 最近，我遇到了一个这样的任务：将项目插入到特定索引处的现有数组中。 听起来很容易而且很普通，但是需要进行一些研究才能弄清楚。

// The original array
    var array = ["one", "two", "four"];
    // splice(position, numberOfItemsToRemove, item)
    array.splice(2, 0, "three");
    
    array;  // ["one", "two", "three", "four"]

If you aren't adverse to extending natives in JavaScript, you could add this method to the Array prototype:

如果您不反对在JavaScript中扩展本机，则可以将此方法添加到Array原型中：

Array.prototype.insert = function (index, item) {
      this.splice(index, 0, item);
    };

I've tinkered around quite a bit with arrays, as you may have noticed:

您可能已经注意到，我对数组进行了很多修改：

*  [Remove an Item From an Array][]
    
    [从数组中删除项目][Remove an Item From an Array]
 *  [Clone Arrays][]
    
    [克隆数组][Clone Arrays]
 *  [Empty Arrays][]
    
    [空数组][Empty Arrays]
 *  [Sort Arrays][]
    
    [排序数组][Sort Arrays]

Arrays are super useful -- JavaScript just makes some tasks a bit more ... code-heavy than they need to be. Keep these snippets in your toolbox for the future!

数组非常有用-JavaScript只会使某些任务变得更多……代码繁重。 将这些摘要保存在您的工具箱中，以备将来使用！

> 翻译自: [https://davidwalsh.name/array-insert-index][https_davidwalsh.name_array-insert-index]

javascript中索引

[Remove an Item From an Array]: https://davidwalsh.name/remove-item-array-javascript
[Clone Arrays]: https://davidwalsh.name/javascript-clone-array
[Empty Arrays]: https://davidwalsh.name/empty-array
[Sort Arrays]: https://davidwalsh.name/array-sort
[https_davidwalsh.name_array-insert-index]: https://davidwalsh.name/array-insert-index