title: Why doesn't go my props to child component when I changed my props in Main Component?
body: <p>When I change my state, I can read newData in Main Component but my update state doesn't go my ChildComponent. I read only initialData in my ChildComponent. Why doesn't go my new props to ChildComponent? or Why doesn't reRender my ChildComponent ?</p>
  <pre><code>class Main extends Component{
   constructor(props) {
          super(props);
          this.state = {
            data: &quot;initalData&quot;,
          }
  }
  
  componentDidMount(){
  this.changeState();
  }
  
  changeState(){
  this.setState({data: &quot;newData&quot;})
  }
  
  render(){
  console.log(&quot;my data in Main :&quot;,this.state.data)
  return(
  &lt;ChildComponent dataProps={this.state.data}&gt;
  )
  }
  
  class ChildComponent extends Component{
  constructor(props) {
          super(props);
          const getData = props.dataProps;
          console.log(&quot;getData is &quot;,getData)
          this.state = {
            ...,
          }
  }
  }
  </code></pre>