Q296: Can useRef be used to store previous values? - React & Modern Frontend (445 Qs)

Yes, useRef is a common pattern when you want to compare current and previous props or state without causing re-renders.

Example: Storing previous state value

 import { useEffect, useRef, useState } from 'react';
 
 function PreviousValueExample() {
   const [count, setCount] = useState(0);
   const prevCountRef = useRef();
 
   useEffect(() => {
     prevCountRef.current = count;
   }, [count]);
 
   const prevCount = prevCountRef.current;
 
   return (
     <div>
       <p>Current: {count}</p>
       <p>Previous: {prevCount}</p>
       <button onClick={() => setCount(c => c + 1)}>Increment</button>
     </div>
   );
 }