**Course Title:** Swift Programming: From Basics to Advanced Development **Section Title:** Control Flow and Functions **Topic:** Write Swift programs that utilize control flow and functions.(Lab topic) Now that you have learned about conditional statements, loops, and functions, it's time to practice writing Swift programs that utilize control flow and functions. In this lab, you'll work on three exercises that demonstrate the application of control flow and functions in real-world scenarios. **Exercise 1: Rock, Paper, Scissors** Create a Rock, Paper, Scissors game that allows two players to play against each other. The game should use a function to determine the winner based on the players' choices. Here's a starting point for your code: ```swift enum Choice: String { case rock case paper case scissors } func determineWinner(_ player1: Choice, _ player2: Choice) -> String { // Your code here } let player1 = Choice.rock let player2 = Choice.scissors let winner = determineWinner(player1, player2) print(winner) ``` To complete this exercise, you'll need to implement the `determineWinner(_:_:)` function using a switch statement or if-else statements to determine the winner based on the game's rules. For example, rock beats scissors, scissors beats paper, and paper beats rock. **Solution** ```swift func determineWinner(_ player1: Choice, _ player2: Choice) -> String { switch (player1, player2) { case (.rock, .scissors), (.scissors, .paper), (.paper, .rock): return "Player 1 wins!" case (.scissors, .rock), (.paper, .scissors), (.rock, .paper): return "Player 2 wins!" default: return "It's a tie!" } } ``` **Exercise 2: Temperature Conversion** Write a program that converts temperature from Celsius to Fahrenheit or Fahrenheit to Celsius. The program should use functions to perform the conversions and a switch statement to determine which conversion to perform based on user input. Here's a starting point for your code: ```swift func celsiusToFahrenheit(_ celsius: Double) -> Double { // Your code here } func fahrenheitToCelsius(_ fahrenheit: Double) -> Double { // Your code here } print("Enter 1 for Celsius to Fahrenheit conversion or 2 for Fahrenheit to Celsius conversion:") var choice = readLine() switch choice { case "1": print("Enter temperature in Celsius:") var celsius = Double(readLine()!)! let fahrenheit = celsiusToFahrenheit(celsius) print("\(celsius)°C is equal to \(fahrenheit)°F") case "2": print("Enter temperature in Fahrenheit:") var fahrenheit = Double(readLine()!)! let celsius = fahrenheitToCelsius(fahrenheit) print("\(fahrenheit)°F is equal to \(celsius)°C") default: print("Invalid choice") } ``` To complete this exercise, you'll need to implement the `celsiusToFahrenheit(_:)` and `fahrenheitToCelsius(_:)` functions using simple arithmetic formulas. For example, the formula to convert Celsius to Fahrenheit is `(°C × 9/5) + 32 = °F`. **Solution** ```swift func celsiusToFahrenheit(_ celsius: Double) -> Double { return (celsius * 9/5) + 32 } func fahrenheitToCelsius(_ fahrenheit: Double) -> Double { return (fahrenheit - 32) * 5/9 } ``` **Exercise 3: FizzBuzz** Write a program that prints the numbers from 1 to 100, but for multiples of three, print "Fizz" instead of the number, and for multiples of five, print "Buzz" instead of the number. For numbers that are multiples of both three and five, print "FizzBuzz". Here's a starting point for your code: ```swift for i in 1...100 { // Your code here } ``` To complete this exercise, you'll need to use a combination of if-else statements and modulus operator (`%`) to check if a number is a multiple of three or five. **Solution** ```swift for i in 1...100 { if i % 3 == 0 && i % 5 == 0 { print("FizzBuzz") } else if i % 3 == 0 { print("Fizz") } else if i % 5 == 0 { print("Buzz") } else { print(i) } } ``` **Conclusion** In this lab, you have written Swift programs that utilize control flow and functions to solve real-world problems. You have learned how to use functions to perform tasks, how to use switch statements to determine which code to execute, and how to use if-else statements to make decisions. I encourage you to leave a comment or ask for help if you have any questions or concerns about the material. Next, we will explore the topic of "Understanding optionals and unwrapping techniques" in the Optionals and Error Handling section. For further learning, I recommend visiting the following resources: * [Swift documentation on Control Flow](https://docs.swift.org/swift-book/ReferenceManual/ControlFlow.html) * [Swift documentation on Functions](https://docs.swift.org/swift-book/ReferenceManual/Functions.html) * [Ray Wenderlich's tutorial on Control Flow in Swift](https://www.raywenderlich.com/104268/advanced-control-flow-swift)