src\App.js第5:3行：“状态”没有定义

Question

import React, { Component } from 'react';

class App extends Component {
  state = { 

   }
  render() { 
    return ( 
      <h1>hlw</h1>
     );
  }
}
 
export default App;

Answer 1

您必须像这样定义状态：

import React, { Component } from 'react';

class App extends Component {
   constructor(props) {
      super(props);
      this.state = { };
   }
   render() {
      return (
        "hlw"
      );
   }
}

export default App;

我建议你读一下《反应》杂志来了解更多。