What is a Pointer?

Part of the Logic & Flow section of Coddy's C journey — lesson 1 of 63.

Think of your computer's memory like a giant apartment building with thousands of rooms. Each room has a unique address, and each room can store one piece of data. When you create a variable in C, it gets assigned to one of these rooms.

A pointer is a special type of variable that doesn't store regular data like numbers or characters. Instead, it stores the address of another variable's memory location. Think of it like writing down someone's apartment number on a piece of paper - the paper doesn't contain the person, but it tells you exactly where to find them.

int age = 25;        // This creates a variable 'age' in memory
int *ptr;            // This creates a pointer that can store an address

In this example, age is stored at some memory address (let's say room 1004), and ptr is a pointer variable that could store the address 1004 to "point to" the age variable.

Pointers are one of C's most powerful features because they allow you to directly work with memory addresses, making your programs more efficient and enabling advanced techniques like dynamic memory allocation and complex data structures.

Cheat sheet

A pointer is a variable that stores the memory address of another variable, rather than storing data directly.

To declare a pointer, use the * operator:

int age = 25;        // Regular variable
int *ptr;            // Pointer variable that can store an address

Pointers allow direct memory manipulation and enable advanced programming techniques like dynamic memory allocation and complex data structures.

Try it yourself

This lesson doesn't include a code challenge.

Test yourself

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All lessons in Logic & Flow

1Pointers Fundamentals

What is a Pointer?Declaring Pointers The Address-Of Operator (&)The Dereference Operator (*)NULL Pointers Recap: Pointer Basics

4Project: Simple Text Utility

Project Overview Counting Characters

Counting Vowels

Convert to Uppercase

Final Output

7Structures (structs)

What is a Struct?Declaring a Struct Creating Struct Variables Accessing Struct Members Initializing Structs Recap: Student Data Struct

10Enums and Typedef

enum for Named Constants Declaring and Using Enums Enums in Switch Statements Using typedef for Type Aliases typedef with Structs Recap: Typedef & Enum Practice