Stack Memory and Heap Memory in Javascript

In JavaScript, stack and heap memory are used to manage the allocation and deallocation of memory for variables, objects, and functions. Here's a concise overview:

Stack Memory

Characteristics:

• Fast Access: Memory allocation and deallocation follow the Last In, First Out (LIFO) principle.

• Fixed Size: Typically limited in size.

• Automatic Management: Managed by the JavaScript engine, automatically handling memory for function calls, variables, and execution context.

Use Cases:

• Primitive Data Types: Stores variables of primitive data types (e.g., number, string, boolean).

• Function Calls: Stores function arguments and local variables.

• Execution Context: Keeps track of function calls and their local execution contexts.

Heap Memory

Characteristics:

• Dynamic Allocation: Memory can be allocated and freed at any time.

• Larger Size: Typically larger than the stack.

• Manual Management: Requires garbage collection to manage memory allocation and deallocation.

Use Cases:

• Objects: Stores objects, arrays, and functions.

• Complex Data Types: Handles larger and more complex data structures.

• Persistent Data: Keeps data that needs to persist beyond the scope of a single function call.

Example

javascriptCopy codefunction example() {
  // Primitive data stored in stack
  let num = 42;
  let str = "Hello, World!";

  // Object stored in heap
  let obj = {
    key: "value"
  };

  // Function stored in heap
  let func = function() {
    console.log("Function in heap");
  };
}

example();

In this example, num and str are stored in the stack, while obj and func are stored in the heap. This distinction helps optimize memory usage and access times in JavaScript.