react componentdidmount et useeffect code example
Example 1: use effect like component did mount
useEffect(() => {
console.log('I am the new componentDidMount')
}, [])
// Don't forget the empty array at the end
Example 2: 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