title: how to update a parent state most efficiently if its reference state got updated
body: <p>I am using Reactjs for my project. if I have states like this:</p>
  
  <pre><code>state = {
     child:menuList
     parent1:{
       key1:'some value',
       key2:'some value'
     }
     parent2:{
       key1:'some value',
       key2:'some value'
     }
     parent3:{
       key1:'some value',
       key2:'some value'
     }
  }
  componentDidMount(){
     const {child} = this.state;
     let {parent1,parent2,parent3} = this.state
     parent1.key3=child;
     parent2.key3=child;
     parent3.key3=child;
     this.setState({
         parent1,
         parent2,
         parent3
     })
  
  
  }
  </code></pre>
  
  <p>child state is reference of parent1, parent2 and parent3</p>
  
  <p>If I update child state like this: <code>this.setState({child:menuList2})</code>, will the parent1, parent2, and parent3 be automatically updated?</p>
  
  <p>If not, what is the most efficient way to update parent1, parent2 and parent3 state if child state got updated</p>