While loop in Swift - Mini Project: Build & Apply

Counting Down with a While Loop

📖 Scenario: Imagine you have a rocket that needs to count down before launch. You want to create a simple program that counts down from a number to zero.

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

📋 What You'll Learn

Create a variable called count with the value 5

Create a variable called zero with the value 0

Use a while loop that runs as long as count is greater than or equal to zero

Inside the loop, print the current value of count

Inside the loop, decrease count by 1 each time

💡 Why This Matters

🌍 Real World

Counting down is used in many real-world situations like rocket launches, game timers, or cooking timers.

💼 Career

Understanding loops is essential for programming tasks that require repetition, such as processing data, animations, or user interactions.

1

Create the starting number

Create a variable called count and set it to 5.

Swift

# Your code here

Need a hint?

Use var to create a variable and assign the number 5 to count.

2

Create the zero value

Create a variable called zero and set it to 0.

Swift

var count = 5
# Your code here

Need a hint?

This variable will be used to compare in the loop condition.

3

Write the while loop

Write a while loop that runs as long as count is greater than or equal to zero. Inside the loop, print count and then subtract 1 from count.

Swift

var count = 5
var zero = 0
# Your code here

Need a hint?

Use while count >= zero { ... } and inside the braces print and decrease count.

4

Run and see the countdown

Run the program to print the countdown from 5 to 0.

Swift

var count = 5
var zero = 0
while count >= zero {
    print(count)
    count -= 1
}
# Your code here

Need a hint?

The program should print numbers from 5 down to 0, each on its own line.