Programmer Group

catalogue Promise summarized it by himself   1,   Error type   2,   error handling   3,   Error object   4,promise   State change understanding promise   5,promise   Use of   7. Why Promise   8,Promise   Syntax api   9. The promise key throws an error message   ...

1. Variable declaration let is used to declare a variable A variable is not promoted, that is, it cannot be used until it is declared The declaration cannot be repeated It has a block level scope and is only valid in the current scope const is used to declare a constant The variable declaration is not promoted, that is, the variable can ...

         Today is the second day of the National Day holiday. I've been playing for a day. Today, I'll sort out the ideas of data analysis homework written in the previous two days and type the manuscript for the experimental report. It is a reference for the little partners who are interested in reptiles ...

EasyExcel experience Video tutorial: 2 hours to quickly master EasyExcel report import and export - black horse programmer Hangzhou school district Reference Blog: Alibaba-EasyExcel-Simple and efficient completion of Excel report import and export) Note: The reference blog is based on the materials that the course instructor has done we ...

1, Construction of development environment 1.1 develop a suitable language for Hongmeng Java: suitable for mobile application developmentC/C + +: suitable for hardware developmentJavaScript: suitable for card developmentCangjie (coming soon) The differences in Java/JS card scenario capabilities are shown in the following table: sceneJava ca ...

Cross domain problem summary 1. Why is there a cross domain problem? The reason is that the browser adopts the Same origin policy for security 2. What is homology strategy? 1. Homology strategy is composed of Netscape A well-known security policy is proposed, which is now supported by all JavaScript All browsers will use this strategy. ...

Vue source code Vue Router (IV) path switching The learning content and article content are from Mr. Huang Yi Uncover the source code of Vue.js2.0, Vue.js 3.0 core source code analysis The source code analyzed here is Vue.js of Runtime + Compiler Debug code: node_modules\vue\dist\vue.esm.js Vue version: Vue.js 2.5.17-beta The more ...

ES6 New features of ES6 let & const const is used to represent constants (it is not allowed to change after declaration. Once declared, it must be initialized, otherwise an error will be reported) //ES6 constant cannot be modified const b=2; b=3;//Uncaught TypeError: Assignment to constant variable. console.log(b); Variables decl ...

Vue content distribution 9, Content distribution In Vue.js, we use the < slot > element as the exit to carry the distribution content. The author calls it a slot, which can be applied in the scenario of composite components; 1. Test content distribution: For example, prepare to make a to-do component (todo), which is composed of t ...

This article will explain in detail   Prototype chain inheritance, constructor based inheritance (call method inheritance), combinatorial inheritance, parasitic combinatorial inheritance, class class class inheritance 1, Prototype chain inheritance Prototype chain inheritance is to assign a display prototype to the subclass constructor, ...