Are use effect and componentDidMount the same thing?

Question

JavaScript

use effectin React 16 has the same/similar functionality and purpose as componentDidMountin React 15?

Answer 1

useEffect is wider

componentDidMount() {
  window.addEventListener('mousemove', () => {})
}

componentWillUnmount() {
  window.removeEventListener('mousemove', () => {})
}

useEffect(() => {
  window.addEventListener('mousemove', () => {});

  // returned function will be called on component unmount 
  return () => {
    window.removeEventListener('mousemove', () => {})
  }
}, [])