Insert element _ javascript at a specified position in a specific index of the JS Array

Recently, I encountered the following requirement: insert an element to a specific index of an existing array. The following is a specific implementation. Do not miss many tasks related to arrays. It sounds very simple, but this is not always the case, and developers often do not use it. Recently, I encountered the following requirement: insert an element to a specific index of an existing array. It sounds easy and common, but it takes some time to study it.

// Original array var array = ["one", "two", "four"]; // splice (position, numberOfItemsToRemove, item) // concatenation function (index location, number of elements to be deleted, element) array. splice (2, 0, "three"); array; // The current array looks like this ["one", "two", "three", "four"]

If you are not disgusted with the extension of native JavaScript, you can add this method to the Array prototype:

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

In this case, you can call:

Var nums = ["one", "two", "four"]; nums. insert (2, 'three '); // note the array index, [, 2 ..] array // ["one", "two", "three", "four"]