component will unmount react hooks code example

Example 1: component unmount hooks

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

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

Example 2: useeffect with cleanup

useEffect(() => {
	//your code goes here
    return () => {
      //your cleanup code codes here
    };
  },[]);

Example 3: replace componentwillmount with hooks

useEffect(() => {
	//will be called on every load
})

useEffect(() => {
	//will be called on component mount
  window.addEventListener('mousemove', () => {});

  // returned function will be called on component unmount 
  return () => {
    window.removeEventListener('mousemove', () => {})
  }
}, []) // <---- empty array at end will cause to only run on first load

Example 4: useeffect react

useEffect(() => {
	//  code goes here
    return () => {
      // cleanup code codes here
    };
  },[]);

Example 5: useeffect componentdidmount

import React, { useState, useEffect } from 'react';
function Example() {
  const [count, setCount] = useState(0);

  // Similar to componentDidMount and componentDidUpdate:  
  useEffect(() => {    
    // Update the document title using the browser API    
    document.title = `You clicked ${count} times`;  
  });

  );
}

Example 6: componentwillunmount hooks

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

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