Core Module
12 min forge

C++ Pointers Basics

Understanding addresses and pointers β€” the foundation of memory manipulation.

C++ Pointers Basics

πŸ“˜ What is it

A pointer is a variable that stores the memory address of another variable. Pointers are one of the most powerful (and dangerous) features of C++.

⚑ When to use

For dynamic memory allocation, efficient data passing, and implementing complex data structures like Linked Lists and Trees.

🧠 Time complexity

  • Dereferencing: $O(1)$
  • Address access: $O(1)$

πŸ’» Code example

cpp Standard
int var = 20;
int *ptr = &var; // ptr stores address of var

std::cout << "Value: " << *ptr << std::endl; // Dereferencing: 20
std::cout << "Address: " << ptr << std::endl; // Address in hex

❌ Common mistakes

  • Dangling Pointers: Pointing to memory that has been freed.
  • Null Pointer Dereference: Trying to access value of a nullptr.
  • Confusing the pointer address with the value it points to.