The answer
Use let/const (no accidental globals), clear timers, remove event listeners, do not close over large objects unnecessarily, use WeakMap/WeakSet for caches, bound cache sizes (LRU), and null out references when no longer needed.
Memory Management in JavaScript: A Complete Guide
How do you avoid memory leaks in JavaScript?
More FAQs in Memory Management in JavaScript: A Complete Guide
Automatically. The engine allocates memory (stack for primitives, heap for objects), you use it, and the garbage collector frees unreachable memory. You do not manually allocate or free memory like in C/C++.
Stack stores primitives and references (fast, LIFO, per-function frames). Heap stores objects, arrays, and functions (unstructured, managed by the GC). Variables hold references to heap objects.
Accidental globals (x = 5 without let), forgotten timers (setInterval never cleared), event listeners on detached DOM elements, closures keeping large objects alive, unbounded caches, and detached DOM references.
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