⚡ MORNING (8 AM – 12 PM): Core JavaScript Power-Up

🎯 Focus:

Get crystal-clear on the JS fundamentals they will test.

🔹 Concepts to Review

• Closures, Scope, Hoisting

  function counter() {
    let count = 0;
    return () => ++count;
  }
  const inc = counter();
  console.log(inc()); // 1
  console.log(inc()); // 2
  
  

  → Be ready to explain how closures preserve state.

• Event Loop / Async JS

  console.log("A");
  setTimeout(()=>console.log("B"),0);
  Promise.resolve().then(()=>console.log("C"));
  console.log("D");
  // Output: A D C B
  
  

  → Practice explaining why (micro vs macro tasks).

• Array/Object Mastery

  • map, filter, reduce, find, some, every
  • destructuring, rest/spread
  • shallow vs deep copy

• Debounce & Throttle

  Understand their purpose and how to implement them.

🔹 Quick Review Links

• JavaScript.info
• Frontend Interview Handbook – JS

🧠 AFTERNOON (12 PM – 4 PM): React Focus Block

🎯 Focus:

Show mastery of React fundamentals + component logic.

🔹 React Hooks (know these cold)

• useState / useEffect

  const [count, setCount] = useState(0);
  useEffect(() => {
    console.log("Count changed:", count);
    return () => console.log("Cleanup"); // unmount
  }, [count]);
  
  

• useCallback / useMemo

  • Prevent unnecessary re-renders.

• Controlled Components

  <input value={name} onChange={e => setName(e.target.value)} />
  
  

• Conditional Rendering

  {isLoading ? <Spinner /> : <DataList />}