为什么打印this显示state正常，单独打印state，值却为空，这是什么情况

Question

问题遇到的现象和发生背景

用代码块功能插入代码，请勿粘贴截图

我的解答思路和尝试过的方法

我想要达到的结果

import React from "react";
import Search from "./Search/Search";
import Content from "./Content/Content";
import './App.css'
export default class App extends React.Component {
  state = {value:''}
  showDate = (date) => {
    this.setState({value:date});
    console.log(this.state);
    console.log(this);
  }
  render() {
    return (
      <div className="home">
        <Search showDate={this.showDate} />
        <Content date = {this.state.value} />
      </div>
    );
  }
}


![img](https://img-mid.csdnimg.cn/release/static/image/mid/ask/858738185566162.png "#left")

Answer 1

setState的异步问题，加个setTimeout或者回调

import React from "react";
import Search from "./Search/Search";
import Content from "./Content/Content";
import './App.css'
export default class App extends React.Component {
  state = {value:''}
  showDate = (date) => {
    this.setState({value:date});
    setTimeout(()=>{
       console.log(this.state);
    })
   
    console.log(this);
  }
  render() {
    return (
      <div className="home">
        <Search showDate={this.showDate} />
        <Content date = {this.state.value} />
      </div>
    );
  }
}
 
 
![img](https://img-mid.csdnimg.cn/release/static/image/mid/ask/858738185566162.png "#left")