Common pointer errors - Mini Project: Build & Apply

Common pointer errors

📖 Scenario: You are learning how to use pointers in C. Pointers are variables that store memory addresses. Sometimes, mistakes with pointers cause programs to crash or behave wrongly. This project will help you understand common pointer errors and how to fix them.

🎯 Goal: You will create a simple C program that uses pointers correctly. You will set up a pointer, assign it to a variable's address, use it to change the variable's value, and then print the result without errors.

📋 What You'll Learn

Create an integer variable with a specific value

Create a pointer to an integer and assign it the address of the variable

Use the pointer to change the variable's value

Print the updated value using the pointer

💡 Why This Matters

🌍 Real World

Pointers are used in C programming to efficiently manage memory and work with data structures like linked lists and trees.

💼 Career

Understanding pointers is essential for systems programming, embedded development, and performance-critical applications.

1

Create an integer variable

Create an integer variable called num and set it to 10.

C

# Create an integer variable called num and set it to 10
// Your code here

Need a hint?

Use int num = 10; inside the main function.

2

Create a pointer and assign address

Create a pointer to an integer called ptr and assign it the address of num using the & operator.

C

#include 

int main() {
    int num = 10;
    
    // Create a pointer to int called ptr and assign it the address of num
    // Your code here
    
    return 0;
}

Need a hint?

Use int *ptr = # to create the pointer and assign the address.

3

Change variable value using pointer

Use the pointer ptr to change the value of num to 20 by dereferencing the pointer with *ptr = 20;.

C

#include 

int main() {
    int num = 10;
    int *ptr = #
    
    // Change the value of num to 20 using the pointer ptr
    // Your code here
    
    return 0;
}

Need a hint?

Use *ptr = 20; to change the value pointed to by ptr.

4

Print the updated value using pointer

Print the updated value of num by dereferencing the pointer ptr using printf("%d\n", *ptr);.

C

#include 

int main() {
    int num = 10;
    int *ptr = #
    *ptr = 20;
    
    // Print the value pointed to by ptr
    // Your code here
    
    return 0;
}

Need a hint?

Use printf("%d\n", *ptr); to print the value.