React list & Keys simple demo

Traversing the array using the map() method produces a list of numbers from 1 to 5 import React, { Component } from 'react'; import ReactDOM from 'react-dom'; import './index.css'; import App from './App'; import * as serviceWorker from './serviceWorker'; import PropTypes from 'prop-types'; const arr=[1,2,3,4,5]; const items=arr.map(val=> ...

Posted by Fitzlegend on Tue, 14 Apr 2020 07:34:29 -0700

Error in v-on handler: "TypeError: Cannot read property 'value' of undefined"

Error in v-on handler: "TypeError: Cannot read property 'value' of undefined" Errors are reported as follows: The above error occurred while running the Vue project because its container was initialized before it was generated. First, check whether there are the following operations //The original operation of fetching dom document.getElementB ...

Posted by BenMo on Tue, 14 Apr 2020 07:35:17 -0700

Cannot read property 'value' of undefined

Error in v-on handler: "TypeError: Cannot read property 'value' of undefined" Errors are reported as follows:The above error occurred while running the Vue project because its container was initialized before it was generated. First, check whether there are the following operations //The original operation of fetching dom document.getElementBy ...

Posted by almystersv on Tue, 14 Apr 2020 07:11:20 -0700

Four Operational Generators for Primary School

Github project address: https://github.com/bravedreamer/test/tree/master/Arithmetic Online preview: https://bravedreamer.github.io/test/Arithmetic/index.html Project Partner: Wu Shangqian 3118004977 Wu Maoping 3118004976 1. Title Description Implements a command line program that automatically generates four arithmetic titles for elementary s ...

Posted by VanPEP on Mon, 13 Apr 2020 10:55:17 -0700

Simple demonstration of React event processing

html version: <button onclick="activateLasers()"> Activation button </button> react version <button onClick={activateLasers}> Activation button </button>   You cannot block the default behavior by returning false. You must explicitly use preventDefault html version < a href = "ා" onclick = "con ...

Posted by sevenfive on Mon, 13 Apr 2020 10:11:52 -0700

Class component, functional component, JSX syntax, data-driven design idea and event binding, TodoList function, etc. in React

What is JSX syntax In JSX syntax, there are two types of tags: 1. Normal html tags (lowercase initial) 2. Component label (capitalized)   Using React to write TodoList function src/TodoList.js import React,{Fragment} from 'react'; function TodoList() { return ( <Fragment> <input type="text" /> <ul> ...

Posted by joviyach on Mon, 13 Apr 2020 09:15:16 -0700

React Props simple demo

The main difference between state and props is that props is immutable, and state can be changed according to the interaction with users. Set the default value for props through the defaultProps property of the component class import React, { Component } from 'react'; import ReactDOM from 'react-dom'; import './index.css'; import App from './A ...

Posted by mottwsc on Mon, 13 Apr 2020 07:51:57 -0700

Click the mouse to show love + socialist values + random color text + mouse cursor custom image

js animation - click to show love Just put the following JS code before < / body > <script type='text/javascript' src='//api.dujin.org/js/aixintexiao.js'></script> Full code: <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, i ...

Posted by aconite on Sun, 12 Apr 2020 21:45:10 -0700

vue2.x learning notes

Next, the previous content: https://www.cnblogs.com/yanggb/p/12586416.html. Input binding of forms The input binding of forms is a very important part, because all business systems are inseparable from the input function of basic forms, so it is necessary to carefully grasp the relevant knowledge points. Basic usage You can use the [v-mode ...

Posted by rishiraj on Sat, 11 Apr 2020 20:06:03 -0700

One of webpack learning, basic use and management of resources

Learning is in the Chinese web pack, just this record for later review; (https://doc.webpack-china.org/guides/getting-started/#-) Write before: I think there are four basic modules of webpack that I should know before learning: 1. Entrance 2. Export 3.loader 4. Plug-ins I. Basic Use Follow the steps ...

Posted by dineshsjce on Sat, 11 Apr 2020 09:37:56 -0700