A. If we want only one time useEffect hook work then we will use an empty array.
import React, {useEffect, useState} from "react"; let UseEffect = () => { let intialData = 10; const [myNum, setMyNum] = useState(intialData); useEffect(() => { console.log('hii'); }, []); return ( <> <center> <h1>{myNum}</h1> <buttononClick={() =>setMyNum(myNum + 1)}>Increase +</button> <button onClick={() => myNum > 0 ? setMyNum(myNum - 1) : setMyNum(0)}>Decrease -</button> </center> </> ) } export default UseEffect;
B. Number of chats using useEffect() hooks
import React, {useEffect, useState} from "react"; let UseEffect = () => { let intialData = 10; const [myNum, setMyNum] = useState(intialData); useEffect(() => { document.title = `Chats(${myNum})`; }); return ( <> <center> <h1>{myNum}</h1> <buttononClick={() =>setMyNum(myNum + 1)}>Increase +</button> <button onClick={() => myNum > 0 ? setMyNum(myNum - 1) : setMyNum(0)}>Decrease -</button> </center> </> ) } export default UseEffect;