Call stack behavior in C++ - Mini Project: Build & Apply

Call Stack Behavior

📖 Scenario: Imagine you are baking a layered cake. Each layer depends on the previous one being ready. Similarly, in programming, functions call other functions, and the computer keeps track of these calls using a call stack.

🎯 Goal: You will write a simple C++ program with three functions calling each other. You will observe how the call stack works by printing messages when entering and exiting each function.

📋 What You'll Learn

Create three functions named first, second, and third.

Each function should print a message when it starts and when it ends.

The first function calls second, and second calls third.

Call the first function from main.

Print messages exactly as instructed to show the call stack behavior.

💡 Why This Matters

🌍 Real World

Understanding the call stack is important for debugging programs and knowing how your computer runs your code step-by-step.

💼 Career

Software developers and engineers use call stack knowledge to fix bugs, optimize code, and understand program flow.

1

Create the third function

Write a function called third that prints "Entering third" when it starts and "Exiting third" when it ends.

C++

#include 

void third() {
    // Your code here
}

int main() {
    return 0;
}

Need a hint?

Use std::cout to print messages inside the third function.

2

Create the second function that calls third

Write a function called second that prints "Entering second" when it starts, calls the third function, then prints "Exiting second" when it ends.

C++

#include 

void third() {
    std::cout << "Entering third" << std::endl;
    std::cout << "Exiting third" << std::endl;
}

void second() {
    // Your code here
}

int main() {
    return 0;
}

Need a hint?

Call the third() function between the two print statements in second().

3

Create the first function that calls second

Write a function called first that prints "Entering first" when it starts, calls the second function, then prints "Exiting first" when it ends.

C++

#include 

void third() {
    std::cout << "Entering third" << std::endl;
    std::cout << "Exiting third" << std::endl;
}

void second() {
    std::cout << "Entering second" << std::endl;
    third();
    std::cout << "Exiting second" << std::endl;
}

void first() {
    // Your code here
}

int main() {
    return 0;
}

Need a hint?

Call the second() function between the two print statements in first().

4

Call first from main and print the output

In the main function, call the first function to start the chain of calls. Then run the program to see the order of messages printed.

C++

#include 

void third() {
    std::cout << "Entering third" << std::endl;
    std::cout << "Exiting third" << std::endl;
}

void second() {
    std::cout << "Entering second" << std::endl;
    third();
    std::cout << "Exiting second" << std::endl;
}

void first() {
    std::cout << "Entering first" << std::endl;
    second();
    std::cout << "Exiting first" << std::endl;
}

int main() {
    // Your code here
}

Need a hint?

Call first() inside main() to start the function calls.