JavaScript

Class Array Object Ah, what difference does it have with a real array object? Can't say that old Maitai, only know the function of arguments object is a class array object, also has the length property, other? Dry Goods on the ministry:First, let's

JavaScript Section 1. What are the actions that cause a memory leak1. Global variables cause2. Closure caused3.dom empty, event not cleared4. Child element Existence reference5. Forgotten Timers2. How to implement AJAX requestsBy instantiating an

1 Arrays-reference typesBuilt-in objects in JavaScript review arrays using two ways to create arrays array object's property length gets the lengths of the array (number of elements)2 Common methods:Detecting ArraysNew in instanceof Array.isarray ()/

First, the constructor of dateThere are four types of date constructors://1. The constructor does not have parameters, it returns the Date object of the current dayvarnow=NewDate ();//2. The parameter of the constructor is the number of milliseconds

The knowledge points and questions that JavaScript has learned so farThe first chapter:1.1 JavaScript the application1) Manipulate animation effects by learning mouse events: OnClick (click event), onmouseover (mouse on), onmouseout (mouse off).2)

// generates an integer random number with a range of [Min,max] function Randomint (Min,max) { if(min ) { throw "does not support negative numbers"; } var number = parseint (Math.random (). toString (). substring (2));

JavaScript usage:1, the script in the HTML must be between tags, can be placed in the HTML page and section;2, you can also put the script in the external. js file, you need to use, in the HTML section: After running the original HTML page is

Garbage Collection principle:Identify the variables that are no longer in use, and then release their memory.The most commonly used garbage collection method in JS is tag cleanup , when variables enter the environment, the variables are marked as "

First look at this statement:(function ($) {...}) (JQuery);1. Principle:Function (ARG) {...}This defines an anonymous function with a parameter of ARGWhen calling a function, the parentheses and arguments are written after the function, and because

To put it simply: let is a bugthat fixes the scope of var and becomes more useful. Let is the better var. var is scoped to a variable defined by var at the scope of the function, scoped to a function body, not the curly braces {} that we

What is JavaScriptJavaScript is a dynamic-type, weakly-typed, prototype-based client-side scripting language used to add dynamic functionality to HTML pages. (Well, what's the most annoying concept?)Dynamic:Determines the data type at run time. A

Front-end interview preparation Notes 1, interview preparation notes I. Common web security and protection principles 1. SQL Injection principles The SQL command is inserted into the web form to submit or enter the query string of the domain name or

Vue implements the method of prompting to save and exit, and vue implements the SAVE and exit method. Assume that you need to edit the text on a page, but do not click Save and jump to the next route. A better way is to give a prompt-"Your edited

Facebook and Google + authorized logon, facebookgoogle In reality, third-party applications such as Facebook and Google + are required to log on to their Web applications (Android and IOS Mobile apps may also exist), which are essentially official

JavaScript generates a time list for the specified range, and javascript generates In a scenario, you need to get every day within the specified time range, satisfying the format of "YYYYMMDD", simple functions, and simple ideas. Preparation The

JavaScript implicit type conversion steps and javascript steps Here, implicit type conversion is a conversion caused by =. If NaN exists, false is returned. If there is a Boolean, the Boolean is converted to a number. Check whether there

Web tile error analysis, web tile Error The instructor asked to create a jigsaw puzzle game on the web. Problems found: After you click the randomly generated puzzle button, the disordered images cannot be restored. Discovery process: each time a

Sample Code for webpack + vuex + axios cross-origin request data, webpackvuex This article describes the sample code for cross-origin request data of webpack + vuex + axios: Use vue-li to build a webpack project and modify the bulid/config/index. js

Based on the implementation method of clicking the external component in Vue to close the component, vue component Vue defines the global click function. The parameter is the click callback function. Vue. prototype. globalClick = function

Webpack: how to package the node. js backend project, webpacknode. js This article describes how to package a node. js backend project in webpack. The details are as follows: Install dependency Copy codeThe Code is as follows:Npm install -- save-dev