Implementing componentDidUpdate using hooks.

useRef.js

  const initialItemsRef = useRef([]);  

useEffect(() => {
    if (userItems.length) {
      const prev = initialItemsRef.current;
      initialWalletsRef.current = <whatToCheckForChanges>;
      const newones = initialItemsRef.current;

      if (newones.length - prev.length === 1) {
        const difference = newones.find((x) => !prev.map((i) => i.AccountNumber).includes(x.AccountNumber));
        // dome stuff here
      }
    }
  }, [whatToCheckForChanges.length]);