JavaScript engines have two places to store data
- Stack: It is a data structure used to store static data. Static data refers to data whose size is known by the engine during compile time. In JavaScript, static data includes primitive values like strings, numbers, boolean, null, and undefined. References that point to objects and functions are also included. A fixed amount of memory is allocated for static data. This process is known as static memory allocation.
- Heap: It is used to store objects and functions in JavaScript. The engine doesn’t allocate a fixed amount of memory. Instead, it allocates more space as required.
Overview:
|
Stack |
Heap |
|---|---|
| Primitive data types and references | Objects and functions |
| Size is known at compile time | Size is known at run time |
| Fixed memory allocated | No limit for object memory |
Example: In the below example object ’employee’ is created in the heap and a reference to it is in the stack.
Javascript
const employee = { name: 'Rajesh', age: 30,};const name="Ram"// Allocates memory for object in heap.Values // in object are primitive,which is why they // are stored in stack.function getname(name) { return name;}// The function return value is given to stack after // being evaluated in the heapconst newEmployee = employee;// The newEmployee object will be stored in the stack and // it will refer to the employee object in heap |
Memory Management in JavaScript
Memory Management in JavaScript
Memory management in JavaScript is handled automatically by the runtime environment, typically the JavaScript engine in web browsers or Node.js. JavaScript uses a garbage collector to manage memory and ensure that developers do not need to manually allocate or deallocate memory.
Contact Us