Introduction

Welcome back, developer! Today, we're diving into Swift control flow, covering:

  • if and switch statements
  • for and while loops
  • Optionals (? and !)

To keep things fun, we're building a Fart Rating App. Users will submit a fart sound, and we’ll rate it based on its "intensity" using loops, conditionals, and optionals. 💨😂

Step 1: Create a New SwiftUI Project

  1. Open Xcode.
  2. Select Create a new Xcode project.
  3. Choose App under iOS.
  4. Name it FartRater.
  5. Select SwiftUI as the interface and Swift as the language.
  6. Click Create! 🚀

Step 2: Understanding Control Flow

If Statements in Swift

Swift uses if statements to make decisions.

let intensity = 7
if intensity > 8 {
    print("Wow, that’s a nuclear fart! 💀")
} else if intensity > 5 {
    print("That’s a solid one! 👌")
} else {
    print("Barely a whisper. 😴")
}

Switch Statements

A switch is great for multiple conditions.

let rating = 3
switch rating {
case 1: print("Barely a squeak! 🐭")
case 2...4: print("Respectable effort. 😎")
case 5...7: print("That’s a real contender! 🔥")
case 8...10: print("Call the authorities! 🚨")
default: print("Invalid rating.")
}

Step 3: Designing the UI

Modify ContentView.swift to create the app UI.

import SwiftUI

struct ContentView: View {
    @State private var intensity: Int? = nil
    @State private var rating: String = ""

    var body: some View {
        VStack {
            Text("Fart Rater")
                .font(.largeTitle)
                .padding()

            Button("Generate Random Fart") {
                intensity = Int.random(in: 1...10)
                rating = rateFart(intensity: intensity!)
            }
            .padding()
            .background(Color.green)
            .foregroundColor(.white)
            .clipShape(Capsule())

            if let intensity = intensity {
                Text("Fart Intensity: \(intensity)")
                    .font(.title2)
                    .padding()
                Text(rating)
                    .font(.title)
                    .bold()
            }
        }
    }
}

Step 4: Implementing the Rating Logic

We need a function to rate the fart. This uses optionals, switch statements, and loops:

func rateFart(intensity: Int) -> String {
    var message = ""
    switch intensity {
    case 1:
        message = "Barely a squeak! 🐭"
    case 2...4:
        message = "Respectable effort. 😎"
    case 5...7:
        message = "That’s a real contender! 🔥"
    case 8...10:
        message = "Call the authorities! 🚨"
    default:
        message = "Invalid rating."
    }

    // Adding dramatic effect with a loop
    for _ in 1...intensity {
        print("💨")
    }

    return message
}

Step 5: Run and Test

  1. Click Run (Cmd + R) in Xcode.
  2. Tap Generate Random Fart.
  3. See the intensity and rating displayed.

Next Steps

✅ You built a Fart Rating App! You now understand:

  • if statements and switch for decision-making
  • Loops (for) for repetition
  • Optionals (?, !) for handling missing values

Next up: "Functions and Closures in Swift" 🚀