Programmer Group

1, Foreword I've seen the interview questions of Holy Grail layout and double wing layout many times. Each time I thought I understood it. As a result, I didn't see it for a while or forgot it. Maybe the interview level I experienced was too low to get it.. In addition, there are generally no such optimization requirements in normal developmen ...

Evening moon preface Originally, I intended to write the principle of the global event bus in Vue, but I found that I wrote less about the custom event, did not understand the operation of the custom event, and it was difficult to write the principle of the global event, so I had this article. 1, v-on instruction To talk about custom event ...

This article has more dry goods. It is recommended to collect! When upgrading from vue2 to vue3, vue3 is compatible with vue2, so vue3 can adopt the optional API of vue2. Because one variable of the optional API exists in many places, if there is a problem, you need to check in multiple functions. When the project is large, it will encounter ...

1,toRaw Returns a proxy object wrapped in reactive or readonly In fact, it is to convert a proxy object into an ordinary object <template> <div> </div> </template> <script> import {ref,reactive,toRaw,readonly,shallowReactive,shallowReadonly,toRefs} from 'vue' export default { name: 'App', setup (props ...

catalogue 1. Composition of JavaScript 1. Three cores 2. Common methods of window objects 2.if selection structure 3. Multiple if selection structure 4. Nested if selection structure 5.switch selection structure 6. Ternary expression 1. Composition of JavaScript 1. Three cores ESMAScript core syntax (Standard Specification) - > ...

ECMAScript 6 adds perfect support for Promises/A + specification, namely Promise type. Once launched, Promise became very popular and became the dominant asynchronous programming mechanism. All modern browsers support ES6, and many other browser API s are based on ES6.Promise is a new reference type in ECMAScript 6, which indicates the final co ...

1. Introduction to websocket Similar to HTTP, WebSocket is a network communication protocol. 1.1. Why do I need WebSocket s We already have the HTTP protocol. Why do we need another protocol? What benefits can it bring? The answer is very simple, because the HTTP protocol has a defect: communication can only be initiated by the client, and ...

In React, the form is divided into two parts: controlled components and uncontrolled components. 4.7.1 controlled components We know that form elements in HTML can input data (or delete), that is, they have their own variable state. For example, in a text box, you can enter or delete content in the text box, and the entered content can be cal ...

1, Write location   you don't need any special software to write JavaScript scripts. An ordinary text editor and a Web browser are enough for programming. Code written in JavaScript must be executed through an HTML/XHTML document. There are currently two ways to call JavaScript. The first method is to put the JavaScript code between t ...

Automatic configuration of data sources To access the data source, we need to import the JDBC scenario first <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jdbc</artifactId> </dependency> We found that he did not auto ...