1.syntax 语法:functional component语法更简单,只需要传入一个props参数,返回一个react片段。class component 要求先继承React.Component然后常见一个render方法,在render里面返回react片段。下面是两者被Babel编译过的代码 2.state 状态:因为function component 知识一个普通的函数所以不可以在其中用this.state , setState(...
functionWelcome=(props)=>{constsayHi=()=>{alert(`Hi${props.name}`);}return(Hello,{props.name}Say Hi)} 把上面的函数组件改写成类组件: 代码语言:javascript 复制 importReactfrom'react'classWelcomeextendsReact.Component{constructor(props){super(props);this.sayHi=this.sayHi.bind(this);}sayHi(){al...
React Class vs Functional Component: 当使用钩子和功能组件时,我的一个函数会不断地重新呈现。 在React中,组件是构建用户界面的基本单元。React组件可以使用类组件或函数组件来定义。 React Class组件: 概念:React Class组件是使用ES6类语法定义的组件。它们...
React class & function component 的区别 React class class App extends React.Component { constructor(props) { super(props);this.state ={ } } render() {return() } } function component functionApp(props) {return() }
区别React classfunction component 写法复杂,继承自React.Component,constructor中接受props参数,render中返回简单、直接接受props作为参数,return返回代码片段 state状态可以使用this.state,setState()等无状态组件 生命周期有无 优点1.需要state来改变内部组件的状态;2.需要使用一些周期函数;3.可以提升性能,有些时候我们需...
componentDidMount(): This ibuilt-in method can be used as soon as you extend the built-in component. React will call it when the component is mounted, meaning it was evaluated and rendered to the DOM. This is equal to using useEffect with empty dependencies in a Functional component, just...
In the world of React, there are two ways of writing a React component. One uses a function and the other uses a class. Recently functional components are becoming more and more popular, so why is that? This article will help you understand the differences between functional and class compon...
2:父组件是Component,子组件是hook importReact,{Component}from'react';classIndexextendsComponent{click=()=>{this.childReset&&this.childReset()}render(){return(<Button onClick={this.click}/><Child ref={(node)=>{this.childReset=node}}/>)}}//子组件importReact,{useImperativeHandle,forwardRef...
Of course, application UIs are dynamic and change over time. a new concept named “state” allows React components to change their output over time in response to user actions without violating this rule. By now we are clear on how to create function component and A Class Component. Then ...
componentWillUnmount(): 组件即将被卸载和销毁之前调用,清理工作在这里进行。 Hooks与Function组件 然后是Function组件,它们就像是那种新兴的无人机,灵活、简洁,而且随着Hooks的加入,它们的功能变得无所不能。 useState 用于添加状态到函数组件中。这就像是给无人机装上了摄像头,突然间它们能做更多事了。