JavaScript: Memory Management

💎JavaScript Memory Management 

👇 Intro: Understanding Memory Management in JavaScript

Ever noticed your web app slowing down over time? Poor memory management could be the culprit. In this article, we’ll break down how JavaScript handles memory and what you can do to write more efficient code.

🧠 Memory management refers to the process of allocating, using, and releasing memory during the life cycle of an application. Every time a variable is declared, or a function is called, memory is allocated. When this memory is no longer needed, it should ideally be released to avoid memory leaks and performance issues.

🧪 How JavaScript Manages Memory ?

Memory Allocation

When you create a variable or object, JavaScript automatically allocates memory in the heap (for objects) or stack (for primitive values).

Memory Usage

During execution, memory is consumed for function calls, variable assignments, and more. JavaScript keeps track of references to these values.

Garbage Collection (GC)

When a value is no longer reachable (i.e., no references to it remain), JavaScript’s GC can reclaim that memory. The most common algorithm used is mark-and-sweep:

• It "marks" all values that are still reachable.
• Then it "sweeps" and frees memory that is no longer reachable.

❓Interview:

Q: What are the reasons for memory leaks, how can we prevent it ?

Memory Leaks occurs when memory is allocated but never released. This can slowly degrade performance.

• Detached DOM Nodes, when an element is removed but JS still references it
• Unclear Intervals / timers
• Closures holding on to outer scope variables
• Event listeners that are still bound but not removed

💻 Example:

>>> Memory handling

💬 Gotcha to Watch For:

Clear intervals and timeouts, remove event listeners, Minimise use of global variables and use tools like Browser Dev-Tools or Performance tab.

⏳Coming up next: JavaScript Performance & Optimisation >>>