什么是react懒加载

//OtherComponent.js 文件内容
 
import React from 'react'
const OtherComponent = ()=>{
  return (
    <div>
      我已加载
    </div>
  )
}
export default OtherComponent
 
// App.js 文件内容
import React from 'react';
import './App.CSS';
 
 
//使用React.lazy导入OtherComponent组件
const OtherComponent = React.lazy(() => import('./OtherComponent'));
 
 
function App() {
  return (
    <div className="App">
      <OtherComponent/>
    </div>
  );
}
export default App;

import React, { Suspense, Component } from 'react';
import './App.css';
 
//使用React.lazy导入OtherComponent组件
const OtherComponent = React.lazy(() => import('./OtherComponent'));
 
export default class App extends Component {
  state = {
    visible: false
  }
  render() {
    return (
      <div className="App">
        <button onClick={() => {
          this.setState({ visible: true })
        }}>
       
        </button>
           加载OtherComponent组件
        <Suspense fallback={<div>Loading...</div>}>
          {
            this.state.visible
              ?
              <OtherComponent />
              :
              null
          }
        </Suspense>
      </div>
    )
  }
}