How to delete an item in js array

How to delete an item in a js array: 1. Use the splice() function to delete, the syntax format is "array.splice (the starting subscript of the deleted element, 1)"; 2. Use the delete keyword, the syntax Format "delete array[array element index]".

The operating environment of this tutorial: windows7 system, javascript version 1.8.5, Dell G3 computer.

How to delete an item in an array in js

1. Use the splice() function

In JS, you can use the splice() function to delete an item in the array; the splice() method is used to add or delete elements in the array.

Syntax:

splice(index,len,[item])

Comments: This method will change the original array.

splice has 3 parameters, it can also be used toreplace/delete/addone or several values ​​in the array

• index: Array start subscript                                                                                                                                             

• For example: arr = ['a','b','c','d']

Delete---- item is not set

• arr.splice(1,1)   //['a','c','d']         删除起始下标为1，长度为1的一个值，len设置的1，如果为0，则数组不变
  arr.splice(1,2)  //['a','d']          删除起始下标为1，长度为2的一个值，len设置的2

  Description: If only one element is deleted, an array of one element is returned. If no elements were removed, an empty array is returned.

2. Use delete keyword

After delete deletes an element in the array, the subscripted value will be set to undefined, and the length of the array will not Change

delete arr[1] //[‘a’, ,‘c’,‘d’] 中间出现两个逗号，数组长度不变，有一项为undefined

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