While loop in C++ - Mini Project: Build & Apply

Counting Down with a While Loop

📖 Scenario: Imagine you have a rocket that needs to count down before launch. We will write a simple program that counts down from a number to zero using a while loop.

🎯 Goal: Build a C++ program that uses a while loop to count down from 5 to 0 and print each number.

📋 What You'll Learn

Create an integer variable called count and set it to 5

Use a while loop that runs while count is greater than or equal to 0

Inside the loop, print the current value of count

Decrease count by 1 in each loop iteration

Print the countdown numbers on separate lines

💡 Why This Matters

🌍 Real World

Counting down is common in timers, games, and events where you wait before starting something important.

💼 Career

Understanding loops is essential for programming tasks like automation, data processing, and controlling program flow.

1

Set up the countdown variable

Create an integer variable called count and set it to 5.

C++

#include 

int main() {
    // Create an integer variable called count and set it to 5
    // Your code here

    return 0;
}

Need a hint?

Use int count = 5; inside the main function.

2

Write the while loop condition

Add a while loop that runs while count is greater than or equal to 0.

C++

#include 

int main() {
    int count = 5;

    // Add a while loop that runs while count is >= 0
    // Your code here

    return 0;
}

Need a hint?

Use while (count >= 0) { } to start the loop.

3

Print the count and decrease it

Inside the while loop, print the current value of count using std::cout, then decrease count by 1 using count--.

C++

#include 

int main() {
    int count = 5;

    while (count >= 0) {
        // Print count
        // Decrease count by 1
        // Your code here
    }

    return 0;
}

Need a hint?

Use std::cout << count << std::endl; to print and count--; to decrease.

4

Run the program to see the countdown

Add a return 0; at the end of main and run the program to print the countdown from 5 to 0.

C++

#include 

int main() {
    int count = 5;

    while (count >= 0) {
        std::cout << count << std::endl;
        count--;
    }

    // Run the program to see the output
    // Your code here
}

Need a hint?

Run the program and check the output shows numbers from 5 down to 0, each on its own line.