Memory management in OOP refers to how objects are allocated, accessed, and freed in memory. Understanding this helps developers write efficient code and avoid memory leaks.

Variables don’t contain objects — they contain references to objects.

let a = { value: 10 };
let b = a; // b REFERS to the same object as a

b.value = 20;
console.log(a.value); // 20 — a and b reference same object

a = { value: 30 };
console.log(b.value); // 20 — b still points to original

Garbage Collection (GC) is the automatic process of reclaiming memory occupied by objects that are no longer reachable.

1. Mark — GC starts from roots (global variables, stack references) and marks all reachable objects
2. Sweep — Unmarked (unreachable) objects are freed

// 1. Forgotten timers
setInterval(() => { /* holds references */ }, 1000);

// 2. Event listeners not removed
element.addEventListener("click", () => { /* holds reference */ });

// 3. Closures holding large data
function createLeak() {
  const largeData = new Array(1000000);
  return () => console.log(largeData.length);
}

• Nullify references when done with large objects
• Remove event listeners when components are destroyed
• Clear timers/intervals (clearInterval, clearTimeout)
• Use weak references for caches (WeakMap, WeakSet)

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