Chapter 6: Pointers – Handle With Care

Table of Contents

• Table of Contents
• 6.1 What Are Pointers?
• 6.2 Pointer Syntax and Usage
• 6.3 Common Pointer Pitfalls
• 6.4 Exercises
• 6.5 Solutions
  • 6.5.1 Solution 1
  • 6.5.2 Solution 2
  • 6.5.3 Solution 3
• 6.6 What’s Coming in the Next Chapter

6.1 What Are Pointers?

A pointer is a variable that stores the address of another variable.

int x = 10;
int *p = &x;

6.2 Pointer Syntax and Usage

• * is used to declare a pointer and to dereference it.
• & is used to get the address of a variable.

6.3 Common Pointer Pitfalls

• Uninitialized pointers
• Dangling pointers
• Pointer arithmetic

6.4 Exercises

1. Declare a pointer to an integer and assign it the address of a variable.
2. Write a program that swaps two integers using pointers.
3. What happens if you dereference a NULL pointer?

6.5 Solutions

6.5.1 Solution 1

int x = 5;
int *p = &x;

6.5.2 Solution 2

void swap(int *a, int *b) {
    int temp = *a;
    *a = *b;
    *b = temp;
}

6.5.3 Solution 3

Dereferencing a NULL pointer causes undefined behavior (often a crash).

6.6 What’s Coming in the Next Chapter

Next, you’ll learn about arrays and strings in C!

Next Chapter → Arrays and Strings