If the parent has shouldComponentUpdate return fasle, will nested elements be updated?

Question

React

class someClass1 extends Component {
  constructor(props) {
    super(props);
    this.props = props;
  }

        shouldComponentUpdate() {
                return false;
        }
  render() {
    return <div></div>
  	}
}

class someClass1 extends Component {
  constructor(props) {
    super(props);
    this.props = props;
  }
  render() {
    return <span></span>
  	}
}

<someClass1>
    <someClass2/>
</someClass1>

Answer 1

If shouldComponentUpdate returns false, the render method of the current component will not be called. Accordingly, child components will also not start rendering themselves. But it may happen (for example - on a timer) that you call setState in the child component - then it will be updated (regardless of the parent)