本文介绍了在非构造函数中,直接超级调用是非法的,而是使用super。“constructor”()的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
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我是试图写简单点击事件功能的新人。
I am new to react am trying to write a simple click event functionality.
具有此类名的span标签
未知:在类构造函数(16:8)之外的super()
When I click choice the span tag with this class name
尝试修复错误的实际代码库
c>)中的错误将被抛出:'this'不允许在super()之前:UPDATE: If one forgets to call super(props) in constructor(), but then attempts to access this, the following error will be thrown: 'this' is not allowed before super():
Module build failed: SyntaxError: C:/_workspaces/hello-world/some-component.jsx: 'this' is not allowed before super() 20 | class SomeComponent extends React.Component { 21 | constructor(props) { > 22 | this.state = { | ^ 23 | message: 'hello world' 24 | } 25 | }这里有一些关于为什么需要它的信息:
Here's a little more info on why it's required: https://discuss.reactjs.org/t/should-we-include-the-props-parameter-to-class-constructors-when-declaring-components-using-es6-classes/2781
ES6静态没有内部方法,只是一个隐含的 render()
ES6 Static No internal methods, just an implied render()
import React from 'react'; const SomeComponent = ({ message }) => ( <div>{message}</div> ); SomeComponent.propTypes = {}; export default SomeComponent;这篇关于在非构造函数中,直接超级调用是非法的,而是使用super。“constructor”()的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!