Enum methods and computed properties in Swift - Mini Project: Build & Apply

Enum methods and computed properties

📖 Scenario: You are creating a simple app that shows different types of fruits and their colors.

🎯 Goal: Build a Swift enum called Fruit with a method and a computed property to get the fruit's color and description.

📋 What You'll Learn

Create an enum called Fruit with cases apple, banana, and cherry

Add a computed property called color that returns the color of each fruit as a String

Add a method called description() that returns a sentence describing the fruit and its color

Print the description of each fruit

💡 Why This Matters

🌍 Real World

Enums with methods and computed properties help organize related data and behavior, like representing fruit types and their details in an app.

💼 Career

Understanding enums with methods and computed properties is important for writing clean, maintainable Swift code in iOS app development.

1

Create the Fruit enum

Create an enum called Fruit with cases apple, banana, and cherry.

Swift

// Your code here

Need a hint?

Use the enum keyword to define Fruit and list the cases inside curly braces.

2

Add a computed property for color

Add a computed property called color inside the Fruit enum that returns a String with the color for each fruit: "Red" for apple, "Yellow" for banana, and "Red" for cherry.

Swift

enum Fruit {
    case apple
    case banana
    case cherry

    // Your code here
}

Need a hint?

Use a var with a switch on self to return the correct color.

3

Add a method to describe the fruit

Add a method called description() inside the Fruit enum that returns a String describing the fruit and its color, like "An apple is Red." Use the color computed property inside this method.

Swift

enum Fruit {
    case apple
    case banana
    case cherry

    var color: String {
        switch self {
        case .apple: return "Red"
        case .banana: return "Yellow"
        case .cherry: return "Red"
        }
    }

    // Your code here
}

Need a hint?

Define a function that returns a string using self and the color property with string interpolation.

4

Print descriptions of all fruits

Create constants apple, banana, and cherry of type Fruit. Then print the result of calling description() on each constant.

Swift

enum Fruit {
    case apple
    case banana
    case cherry

    var color: String {
        switch self {
        case .apple: return "Red"
        case .banana: return "Yellow"
        case .cherry: return "Red"
        }
    }

    func description() -> String {
        return "An \(self) is \(color)."
    }
}

// Your code here

Need a hint?

Create constants for each fruit case and print their descriptions using the description() method.