ReactJS Cheatsheet: The Ultimate Guide for Senior Developers

This cheatsheet provides a condensed reference for modern React development patterns, focusing on Hooks, Performance, and clean architecture.

### 1. Essential Hooks
– **useState:** `const [state, setState] = useState(initialValue);`
– **useEffect:** For side effects. Remember the dependency array to avoid infinite loops.
– **useMemo:** For memoizing expensive calculations.
– **useCallback:** For memoizing functions passed to child components.

### 2. Ref and DOM Access
Use `useRef` for persistent values that don’t trigger re-renders, or for direct DOM manipulation when necessary.
`const inputRef = useRef(null);`

### 3. Context API for Global State
Avoid ‘prop drilling’ by using React Context.
`const ThemeContext = React.createContext(‘light’);`

### 4. Advanced Patterns
– **HOCs (Higher-Order Components):** For cross-cutting concerns.
– **Render Props:** For sharing logic between components.
– **Custom Hooks:** The preferred way to encapsulate and reuse stateful logic.

VDPL’s engineering team uses this reference to maintain consistency across our large-scale React projects for clients in Delhi NCR.