DEV Community

Nadim Chowdhury
Nadim Chowdhury

Posted on

What is Pointer?

A pointer is a variable that stores the memory address of another variable. In JavaScript, pointers are often abstracted away, but they are still used behind the scenes to manage memory and references to objects or arrays.

Here are some key points about pointers:

Types of Pointers:

  1. Null Pointer: A pointer that doesn't point to any memory location. In JavaScript, this is represented by null or undefined.
  2. Dangling Pointer: A pointer that points to a memory location that has been deleted or freed.
  3. Void Pointer: A pointer that has no associated data type.

Common Usage:

  1. Memory Management: Pointers are used to manage memory dynamically, allocating and deallocating memory as needed.
  2. Data Structures: Pointers are essential in implementing data structures like linked lists, trees, and graphs.
  3. Function Pointers: Pointers can store the address of functions, allowing for more flexible and dynamic programming.
  4. Array and String Handling: In languages like C and C++, pointers are used to access and manipulate arrays and strings efficiently.
  5. Passing by Reference: In languages that support pointers (like C and C++), pointers are used to pass variables by reference to functions, allowing the function to modify the original variable.

Pointer Arithmetic:

In languages like C and C++, pointers support arithmetic operations such as addition, subtraction, and comparison. This allows for efficient traversal of arrays and linked structures.

Pointer in JavaScript:

In JavaScript, pointers are less explicit compared to languages like C and C++. Variables in JavaScript hold references to objects or arrays rather than direct memory addresses. For example:

let obj1 = { name: 'John' };
let obj2 = obj1;  // obj2 is a pointer/reference to obj1 = 'Doe';
console.log(;  // Outputs: Doe
Enter fullscreen mode Exit fullscreen mode

In this example, obj1 and obj2 both point to the same memory location (the same object), so modifying obj2 also affects obj1.


  • A pointer is a variable that holds the memory address of another variable.
  • Pointers are used for memory management, data structure implementation, and more.
  • JavaScript uses references to objects and arrays, which are similar to pointers but are abstracted away and managed by the language.
  • Understanding pointers is essential for efficient memory management and data manipulation in low-level languages like C and C++, while in higher-level languages like JavaScript, pointers are abstracted to make memory management easier and safer.

Disclaimer: This article was created with the help of AI.

Top comments (0)