For-in loop with ranges in Swift - Mini Project: Build & Apply

For-in loop with ranges

📖 Scenario: You are helping a small bakery count the number of cupcakes they bake each day for a week. They want to know the total cupcakes baked from Monday to Sunday.

🎯 Goal: Build a Swift program that uses a for-in loop with a range to sum the cupcakes baked each day and print the total.

📋 What You'll Learn

Create a dictionary called cupcakesBaked with keys as days of the week and values as the number of cupcakes baked.

Create a constant days that holds the range from 1 to 7 representing days Monday to Sunday.

Use a for-in loop with the variable day to iterate over days.

Inside the loop, add the cupcakes baked for each day to a variable totalCupcakes.

Print the total cupcakes baked after the loop.

💡 Why This Matters

🌍 Real World

Counting daily production or sales is common in small businesses to track performance and plan inventory.

💼 Career

Using loops and ranges to process data collections is a fundamental skill for software developers, especially in data processing and automation tasks.

1

Create the cupcakes data

Create a dictionary called cupcakesBaked with these exact entries: 1: 12, 2: 15, 3: 10, 4: 20, 5: 18, 6: 25, 7: 22.

Swift

# Create the cupcakesBaked dictionary with days 1 to 7 and their cupcake counts
# Your code here

Need a hint?

Use a Swift dictionary with integer keys for days and integer values for cupcakes.

2

Create the days range

Create a constant called days that holds the range from 1 to 7 inclusive.

Swift

let cupcakesBaked = [1: 12, 2: 15, 3: 10, 4: 20, 5: 18, 6: 25, 7: 22]
# Create the days range from 1 to 7
# Your code here

Need a hint?

Use the closed range operator ... to include both 1 and 7.

3

Sum cupcakes using a for-in loop

Create a variable called totalCupcakes and set it to 0. Then use a for-in loop with the variable day to iterate over days. Inside the loop, add the cupcakes baked for each day from cupcakesBaked to totalCupcakes. Use optional unwrapping with ?? 0 to handle missing values.

Swift

let cupcakesBaked = [1: 12, 2: 15, 3: 10, 4: 20, 5: 18, 6: 25, 7: 22]
let days = 1...7
# Create totalCupcakes variable and sum cupcakes in a for-in loop
# Your code here

Need a hint?

Remember to initialize totalCupcakes before the loop and use cupcakesBaked[day] ?? 0 to safely get the value.

4

Print the total cupcakes

Write a print statement to display the text Total cupcakes baked: followed by the value of totalCupcakes using string interpolation.

Swift

let cupcakesBaked = [1: 12, 2: 15, 3: 10, 4: 20, 5: 18, 6: 25, 7: 22]
let days = 1...7
var totalCupcakes = 0
for day in days {
    totalCupcakes += cupcakesBaked[day] ?? 0
}
# Print the total cupcakes baked
# Your code here

Need a hint?

Use print("Total cupcakes baked: \(totalCupcakes)") to show the result.