component did mount with hooks code example

Example 1: componentdidmount hooks

For componentDidMount
useEffect(() => {
  // Your code here
}, []);

For componentDidUpdate
useEffect(() => {
  // Your code here
}, [yourDependency]);

For componentWillUnmount
useEffect(() => {
  // componentWillUnmount
  return () => {
     // Your code here
  }
}, [yourDependency]);

Example 2: 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 3: componentwillunmount hooks

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

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

Example 4: useeffect componentdidmount

useEffect(() => {
    messagesRef.on('child added', snapshot => {
    const message = snapshot.val();
    message.key = snapshot.key;

    setMessages(messages.concat(message)); // See Note 1
}, []); // See Note 2

Example 5: componentdidmount in hooks

useEffect(() => {
  // Your code here
}, []);