Hook出现之前我们对比Function components和 class components之间差异性,一般会对比: 渲染性能 纯的组件 hooks出现之后,我们可以得出他们最大的差异性: 函数组件能够捕获渲染的值也就是所谓的capture value 示例 函数组件: constCapture=()=>{const[count,setCount]=useState(0);consthandlerChange=(e)=>{setCount(e...
1. 类组件(Class Component) 类组件是使用 ES6 的类(class)语法定义的 React 组件。它们具有更复杂的功能,特别是在 React 16.8 之前,它们是唯一能够使用状态(state)和生命周期方法的组件。 特点: 使用class 关键字定义,并继承自 React.Component。 能够使用 state 来管理组件的内部状态。 可以使用生命周期方法,如...
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(...
react里面的function组件与class组件 假设场景是有一个父组件,包裹一个function子组件和class子组件 class组件在render过后,定义好的function,可以通过this.func进行调用,并且不会重新再创建 function组件会...
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 components by walking through each one with sample code so that you can dive ...
React Function Component: ref(React 函数组件之:ref) React Function Component: PropTypes(React 函数组件之:PropTypes) React Function Component: TypeScript(React 函数组件之:TypeScript) React Function Component vs Class Component(React 的函数组件和类组件) ...
参考: https://overreacted.io/how-are-function-components-different-from-classes/ https://www.w3cplus.com/react/class-component-vs-function-component.html?expire=1572407286&code=ySIuISmoCpg&sign=c403bc02f809090a84d44dea74418b5c#paywall
import React from 'react'// 创建 Context 填入默认值(任何一个 js 变量)const ThemeContext = React.createContext('light')// 底层组件 - 函数是组件function ThemeLink (props) {// const theme = this.context // 会报错。函数式组件没有实例,即没有 this// 函数式组件可以使用 Consumerreturn <Theme...
Components are regular JavaScript functions that return renderable results. These components can be defined by creating a class with a render method. React will call that method to evaluate what should be rendered to the screen.
One of the main differences between a function and a class is that with the function you are sure the output depends only on the input (not on any history of the previous executions). Ideally in your app you should aim to have as many stateless components as possible, because that nor...