Why getDerivedStateFromProps is called after setState?

Question

React introduced new static method getDerivedStateFromProps(props, state) which is called before every render method, but why? Calling it after prop change makes se

Answer 1

For this case (updating the state based on props change), use:

componentDidUpdate(prevProps) {
  // don't forget to compare props
  if (this.props.userID !== prevProps.userID) {
    this.fetchData(this.props.userID);
  }
}

componentDidUpdate will get called after each update (due to props changes / state changes). so you should check if the prop is changed (by this.props.userID !== prevProps.userID).