What are the methods to clear arrays in javascript

Javascript method to clear an array: 1. Use the splice method, the code is [ary.splice(0,ary.length)]; 2. Assign length to 0, the code is [ary.length = 0;] .

The operating environment of this tutorial: Windows 7 system, JavaScript version 1.8.5, DELL G3 computer.

Javascript method to clear array:

Method 1, splice

var ary = [1,2,3,4]; 
ary.splice(0,ary.length); 
console.log(ary); // 输出 []，空数组，即被清空了

Method 2, length assignment is 0

This method is very interesting. In other languages ​​such as Java, the length of the array is read-only and cannot be assigned. For example,

int[] ary = {1,2,3,4}; 
ary.length = 0;

will report an error in Java and fail to compile.

In JS, it is possible, and the array is cleared. For example,

var ary = [1,2,3,4]; 
ary.length = 0; 
console.log(ary); // 输出 []，空数组，即被清空了

Currently, the clear method of the array in Prototype and the empty method of the array in the mootools library use this method to clear the array.

Method 3, assign value to []

var ary = [1,2,3,4]; 
ary = []; // 赋值为一个空数组以达到清空原数组

The clear method of the Ext.CompositeElementLite class in the Ext library uses this method to clear.

Related free learning recommendations: javascript video tutorial

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