Common methods of js array operation
Traversal is used more when processing JSON arrays in jquery, but adding and removing them does not seem to be too much.
I tried json[i].remove() and json.remove(i) today but it didn’t work. It seems that the JSON data appears in the form of an array in the DOM object of the web page. I checked the relevant JS It's really fun to try out the array operations.
record it.
1. Creation of arrays
var arrayObj = new Array(); //创建一个数组 var arrayObj = new Array([size]); //创建一个数组并指定长度，注意不是上限，是长度 var arrayObj = new Array([element0[, element1[, ...[, elementN]]]]); //创建一个数组并赋值
It should be noted that although the second method creates an array with a specified length, in fact the array is variable length in all cases, that is to say Even if a length of 5 is specified, elements can still be stored outside the specified length. Note: the length will change accordingly.
2. Access to array elements
var testGetArrValue=arrayObj[1]; //获取数组的元素值 arrayObj[1]= "这是新值"; //给数组元素赋予新的值
3. Addition of array elements
arrayObj. push([item1 [item2 [. . . [itemN ]]]]);// 将一个或多个新元素添加到数组结尾，并返回数组新长度 arrayObj.unshift([item1 [item2 [. . . [itemN ]]]]);// 将一个或多个新元素添加到数组开始，数组中的元素自动后移，返回数组新长度 arrayObj.splice(insertPos,0,[item1[, item2[, . . . [,itemN]]]]);//将一个或多个新元素插入到数组的指定位置，插入位置的元素自动后移，返回""。
4. Deletion of array elements
arrayObj.pop(); //移除最后一个元素并返回该元素值 arrayObj.shift(); //移除最前一个元素并返回该元素值，数组中元素自动前移 arrayObj.splice(deletePos,deleteCount); //删除从指定位置deletePos开始的指定数量deleteCount的元素，数组形式返回所移除的元素
5. Interception and merging
arrayObj.slice(start, [end]); //以数组的形式返回数组的一部分，注意不包括 end 对应的元素，如果省略 end 将复制 start 之后的所有元素 arrayObj.concat([item1[, item2[, . . . [,itemN]]]]); //将多个数组（也可以是字符串，或者是数组和字符串的混合）连接为一个数组，返回连接好的新的数组
6. Copy of array
arrayObj.slice(0); //返回数组的拷贝数组，注意是一个新的数组，不是指向 arrayObj.concat(); //返回数组的拷贝数组，注意是一个新的数组，不是指向
7. Sorting of array elements
arrayObj.reverse(); //反转元素（最前的排到最后、最后的排到最前），返回数组地址 arrayObj.sort(); //对数组元素排序，返回数组地址
8. Stringization of array elements
arrayObj.join(separator); //返回字符串，这个字符串将数组的每一个元素值连接在一起，中间用 separator 隔开。
toLocaleString, toString, valueOf: can be regarded as special usages of join, not commonly used
For more related articles on common methods of js array operations, please pay attention to the PHP Chinese website!
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
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1382
52
How do I create and publish my own JavaScript libraries?
Mar 18, 2025 pm 03:12 PM
Article discusses creating, publishing, and maintaining JavaScript libraries, focusing on planning, development, testing, documentation, and promotion strategies.
How do I optimize JavaScript code for performance in the browser?
Mar 18, 2025 pm 03:14 PM
The article discusses strategies for optimizing JavaScript performance in browsers, focusing on reducing execution time and minimizing impact on page load speed.
What should I do if I encounter garbled code printing for front-end thermal paper receipts?
Apr 04, 2025 pm 02:42 PM
Frequently Asked Questions and Solutions for Front-end Thermal Paper Ticket Printing In Front-end Development, Ticket Printing is a common requirement. However, many developers are implementing...
How do I debug JavaScript code effectively using browser developer tools?
Mar 18, 2025 pm 03:16 PM
The article discusses effective JavaScript debugging using browser developer tools, focusing on setting breakpoints, using the console, and analyzing performance.
Who gets paid more Python or JavaScript?
Apr 04, 2025 am 12:09 AM
There is no absolute salary for Python and JavaScript developers, depending on skills and industry needs. 1. Python may be paid more in data science and machine learning. 2. JavaScript has great demand in front-end and full-stack development, and its salary is also considerable. 3. Influencing factors include experience, geographical location, company size and specific skills.
How do I use source maps to debug minified JavaScript code?
Mar 18, 2025 pm 03:17 PM
The article explains how to use source maps to debug minified JavaScript by mapping it back to the original code. It discusses enabling source maps, setting breakpoints, and using tools like Chrome DevTools and Webpack.
How to merge array elements with the same ID into one object using JavaScript?
Apr 04, 2025 pm 05:09 PM
How to merge array elements with the same ID into one object in JavaScript? When processing data, we often encounter the need to have the same ID...
The difference in console.log output result: Why are the two calls different?
Apr 04, 2025 pm 05:12 PM
In-depth discussion of the root causes of the difference in console.log output. This article will analyze the differences in the output results of console.log function in a piece of code and explain the reasons behind it. �...
