In fact, push and pop are usually used more often, but I still write them down for later use.
shift : delete the first item of the original array and return the value of the deleted element; if the array is empty, return undefined
var a = [1,2,3,4,5];
var b = a.shift(); //a:[2,3,4,5] b:1
unshift : Add parameters to the beginning of the original array and return the length of the array
var a = [1,2,3,4,5];
var b = a.unshift(-2,-1); //a: [-2,-1,1,2,3,4,5] b: 7
Note: The test return value under IE6.0 is always undefined, and the test return value under FF2.0 is 7, so the return value of this method is unreliable. When the return value is needed, splice can be used instead of this method. This article comes from www.45it.com
pop : Delete the last item of the original array and return the value of the deleted element; if the array is empty, return undefined
var a = [1,2,3,4,5];
var b = a.pop(); //a:[1,2,3,4] b:5
push : Add parameters to the end of the original array and return the length of the array
var a = [1,2,3,4,5];
var b = a.push(6,7); //a:[1,2,3,4,5,6,7] b:7
concat : Returns a new array, which is composed of adding parameters to the original array
var a = [1,2,3,4,5];
var b = a.concat(6,7); //a: [1,2,3,4,5] b: [1,2,3,4,5,6,7]
splice (start,deleteCount,val1,val2,...): Delete deleteCount items from the start position and insert val1, val2,...
var a = [1,2,3,4,5];
var b = a.splice(2,2,7,8,9); //a:[1,2,7,8,9,5] b:[3,4]
var b = a.splice(0,1); //Same as shift
a.splice(0,0,-2,-1); var b = a.length; //Same as unshift
var b = a.splice(a.length-1,1); //Same as pop
a.splice(a.length,0,6,7); var b = a.length; //Same as push
-------------------------------------------------- ----
Detailed explanation of splice:
The splice function removes one or more elements from an array, inserts a new element at the position of the removed element if necessary, and returns the removed element.
arrayObj.splice( start, deleteCount, [item1[, item2[, . . . [,itemN]]]])
arrayObj is a required option. An Array object.
Start is a required option. Specifies the starting position to remove elements from the array, starting from 0.
deleteCount is required. The number of elements to remove.
item1, item2,. . ., itemN is required. A new element to be inserted at the location of the removed element.
The splice function method in JavaScript can modify arrayObj by removing a specified number of elements starting from the start position and inserting new elements. The return value is a new Array object consisting of the removed elements.
-------------------------------------------------- ----
reverse : Reverse the array
var a = [1,2,3,4,5];
var b = a.reverse(); //a: [5,4,3,2,1] b: [5,4,3,2,1]
sort (orderfunction): Sort the array according to the specified parameters
var a = [1,2,3,4,5];
var b = a.sort(); //a: [1,2,3,4,5] b: [1,2,3,4,5]
slice (start,end): Returns a new array composed of items between the specified start index and the end index in the original array
var a = [1,2,3,4,5];
var b = a.slice(2,5); //a:[1,2,3,4,5] b:[3,4,5]
join (separator): Combine the elements of the array into a string, with separator as the separator. If omitted, the default comma is used as the separator
var a = [1,2,3,4,5];
var b = a.join("|"); //a:[1,2,3,4,5] b:"1|2|3|4|5"
The above is the entire content of this article, I hope you guys will like it.

去掉重复并排序的方法:1、使用“Array.from(new Set(arr))”或者“[…new Set(arr)]”语句,去掉数组中的重复元素,返回去重后的新数组;2、利用sort()对去重数组进行排序,语法“去重数组.sort()”。

本篇文章给大家带来了关于JavaScript的相关知识,其中主要介绍了关于Symbol类型、隐藏属性及全局注册表的相关问题,包括了Symbol类型的描述、Symbol不会隐式转字符串等问题,下面一起来看一下,希望对大家有帮助。

怎么制作文字轮播与图片轮播?大家第一想到的是不是利用js,其实利用纯CSS也能实现文字轮播与图片轮播,下面来看看实现方法,希望对大家有所帮助!

本篇文章给大家带来了关于JavaScript的相关知识,其中主要介绍了关于对象的构造函数和new操作符,构造函数是所有对象的成员方法中,最早被调用的那个,下面一起来看一下吧,希望对大家有帮助。

本篇文章给大家带来了关于JavaScript的相关知识,其中主要介绍了关于面向对象的相关问题,包括了属性描述符、数据描述符、存取描述符等等内容,下面一起来看一下,希望对大家有帮助。

方法:1、利用“点击元素对象.unbind("click");”方法,该方法可以移除被选元素的事件处理程序;2、利用“点击元素对象.off("click");”方法,该方法可以移除通过on()方法添加的事件处理程序。

本篇文章给大家带来了关于JavaScript的相关知识,其中主要介绍了关于BOM操作的相关问题,包括了window对象的常见事件、JavaScript执行机制等等相关内容,下面一起来看一下,希望对大家有帮助。

foreach不是es6的方法。foreach是es3中一个遍历数组的方法,可以调用数组的每个元素,并将元素传给回调函数进行处理,语法“array.forEach(function(当前元素,索引,数组){...})”;该方法不处理空数组。


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Zend Studio 13.0.1
Powerful PHP integrated development environment

Notepad++7.3.1
Easy-to-use and free code editor

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function
