Master React performance optimization techniques for 2024.

// Using useTransition for non-urgent updates
const [isPending, startTransition] = useTransition();

const handleSearch = (query) => {
  // Urgent update: Show immediate UI feedback
  setInputValue(query);
  
  // Mark the state update as non-urgent
  startTransition(() => {
    // Non-urgent update: Data fetching or heavy computation
    setSearchResults(computeResults(query));
  });
};
    

// Deferring expensive computations
const [input, setInput] = useState('');
const deferredInput = useDeferredValue(input);

const results = useMemo(() => {
  return computeExpensiveValue(deferredInput);
}, [deferredInput]);
    

// Custom memoization with deep comparison
const filteredUsers = useMemo(() => {
  return users.filter(user => {
    // Complex filtering logic
    return user.isActive && 
           user.lastLogin > Date.now() - 30 * 24 * 60 * 60 * 1000;
  });
}, [users]);
    

// Memoizing components with React.memo
const UserList = React.memo(({ users }) => {
  return (
    

      {users.map(user => (
        
      ))}
    
  );
}, (prevProps, nextProps) => {
  // Custom comparison function
  return prevProps.users.length === nextProps.users.length &&
         prevProps.users.every((user, i) => 
           user.id === nextProps.users[i].id && 
           user.name === nextProps.users[i].name
         );
});