React-hooks-useState

React-class的setState

import React, {Component} from 'react';

export default class App1 extends Component {
  constructor(props) {
    super(props);
    this.state = {count: 0}
  }
  render() {
    const {count} = this.state
    return (
      

        
count: {count}

        +1

      

    );

  }
  addCount(){
    this.setState({count:this.state.count+1})
  }
}

React-hooks-useState

import React, {useState} from 'react'

function App2() {
  const [count, addCount] = useState(0)
  return (
    

      
count: {count}

       {addCount(count + 1)}}>+1
    

  )

}
export default App2