react-16

React Class components vs Functional components

由 别来无恙 提交于 2021-02-16 18:54:07
问题 Before React16 , class components were used over functional components whenever there is a need to use state or lifecycle methods in your component. In the latest release react introduced Hooks and Effects using which we can use state and lifecycle methods inside our functional components . So is there any reason why still the class components exists? Is there any cases we still have to choose class components over functional 回答1: Here you can see the cases where you will need class

React Class components vs Functional components

由 淺唱寂寞╮ 提交于 2021-02-16 18:53:17
问题 Before React16 , class components were used over functional components whenever there is a need to use state or lifecycle methods in your component. In the latest release react introduced Hooks and Effects using which we can use state and lifecycle methods inside our functional components . So is there any reason why still the class components exists? Is there any cases we still have to choose class components over functional 回答1: Here you can see the cases where you will need class

JSON & REACT 16.8 TypeError: _data_projects_json__WEBPACK_IMPORTED_MODULE_2__.map is not a function

由 浪尽此生 提交于 2020-07-23 06:41:23
问题 The error "TypeError: data_projects_json__WEBPACK_IMPORTED_MODULE_2 _.map is not a function" is thrown when I try to complete the following map function. import React from 'react'; import './Projects.scss' import Data from '../../data/projects.json' function Projects (){ return ( <section id="projects"> <h1>PROJECTS</h1> <div> {Data.map(post => { return( <div className="projects" key={i}> <h2>{post.title}</h2> <img>{post.img}</img> <a>{post.site}</a> <a>{post.repo}</a> </div> ) })} </div> <

JSON & REACT 16.8 TypeError: _data_projects_json__WEBPACK_IMPORTED_MODULE_2__.map is not a function

由 谁说胖子不能爱 提交于 2020-07-23 06:40:29
问题 The error "TypeError: data_projects_json__WEBPACK_IMPORTED_MODULE_2 _.map is not a function" is thrown when I try to complete the following map function. import React from 'react'; import './Projects.scss' import Data from '../../data/projects.json' function Projects (){ return ( <section id="projects"> <h1>PROJECTS</h1> <div> {Data.map(post => { return( <div className="projects" key={i}> <h2>{post.title}</h2> <img>{post.img}</img> <a>{post.site}</a> <a>{post.repo}</a> </div> ) })} </div> <

JSON & REACT 16.8 TypeError: _data_projects_json__WEBPACK_IMPORTED_MODULE_2__.map is not a function

由 删除回忆录丶 提交于 2020-07-23 06:39:05
问题 The error "TypeError: data_projects_json__WEBPACK_IMPORTED_MODULE_2 _.map is not a function" is thrown when I try to complete the following map function. import React from 'react'; import './Projects.scss' import Data from '../../data/projects.json' function Projects (){ return ( <section id="projects"> <h1>PROJECTS</h1> <div> {Data.map(post => { return( <div className="projects" key={i}> <h2>{post.title}</h2> <img>{post.img}</img> <a>{post.site}</a> <a>{post.repo}</a> </div> ) })} </div> <

Uncaught TypeError: Cannot read property 'injection' of undefined [closed]

由 China☆狼群 提交于 2020-05-28 13:31:11
问题 Closed. This question needs debugging details. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 2 years ago . I am getting following error after upgrading react to 16.x Uncaught TypeError: Cannot read property 'injection' of undefined at injectTapEventPlugin (injectTapEventPlugin.js:23) at eval (index.js:53) at Object.<anonymous> (bundle.js:1363) at __webpack_require__ (bundle.js:556) at fn (bundle.js:87) at

getDerivedStateFromProps is not called

由 半世苍凉 提交于 2019-12-13 12:55:15
问题 I use React 16.3.1 and next.js . And I put getDerivedStateFromProps inside the class extending PureComponent . Here is the code: Header.js import { PureComponent } from 'react' ... export default class Header extends PureComponent { constructor (props) { super(props) this.colorAnimationProps = { animationDuration: '0.4s', animationFillMode: 'forwards' } this.colorAnimationStyle = { toColor: { animationName: 'toColor', ...this.colorAnimationProps }, toTransparent: { animationName:

Fragments giving Unexpected token error in React 16.2

由 随声附和 提交于 2019-12-09 14:35:03
问题 I have the following component that renders a series of components. However, I downloaded React 16.2 and tried to use fragments instead of divs, but I get the following error: Error in ./src/containers/answers.js Syntax error: Unexpected token (24:5) 22 | 23 | return ( > 24 | <> | ^ 25 | {AnswersCard} 26 | </> 27 | ) Why am I getting this error when fragments are supposed to be able to replace divs in React 16.2? question ? AnswersCard = ( question.answers.sort(function(a,b) { return (a.count

React: reading data passed as parameter in history.push

由 安稳与你 提交于 2019-12-07 07:17:57
问题 I am new to react and I am trying to send some data as parameter in history.push . Basically I am calling a method on a button click and inside the method I am calling an api. If I get success response I redirect to other page and I need to pass some data as well. Below is my code for that: class Login extends Component { constructor(props) { super(props); this.state = { enteredName: null, enteredPwd: null, rescode: null, userName: null, formatDesc: null, userFormat : null, success: false,

React: reading data passed as parameter in history.push

由 生来就可爱ヽ(ⅴ＜●) 提交于 2019-12-05 15:18:50
I am new to react and I am trying to send some data as parameter in history.push . Basically I am calling a method on a button click and inside the method I am calling an api. If I get success response I redirect to other page and I need to pass some data as well. Below is my code for that: class Login extends Component { constructor(props) { super(props); this.state = { enteredName: null, enteredPwd: null, rescode: null, userName: null, formatDesc: null, userFormat : null, success: false, responseJson : null, }; } state = { enteredName: null, enteredPwd: null, rescode: null, userName: null,
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