Protocol requirements (methods and properties) in Swift - Mini Project: Build & Apply

Protocol requirements (methods and properties) in Swift

📖 Scenario: You are creating a simple app to manage different types of vehicles. Each vehicle must have a name and a way to start it. You will use a protocol to define these requirements.

🎯 Goal: Build a Swift program that defines a protocol with method and property requirements, then create a struct that conforms to this protocol and implements the required method and property.

📋 What You'll Learn

Define a protocol called Vehicle with a read-only property name of type String

Add a method requirement start() in the Vehicle protocol

Create a struct called Car that conforms to the Vehicle protocol

Implement the name property and start() method in the Car struct

Print the car's name and call the start() method to show the output

💡 Why This Matters

🌍 Real World

Protocols are used in Swift to define common behavior that different types can share, such as vehicles having names and start methods.

💼 Career

Understanding protocols is essential for Swift developers to write flexible, reusable, and maintainable code in apps and frameworks.

1

Define the Vehicle protocol

Define a protocol called Vehicle with a read-only property name of type String and a method requirement start().

Swift

# Define the Vehicle protocol with a read-only property 'name' and a method 'start()'
// Your code here

Need a hint?

Use protocol keyword. The property name should be read-only, so use { get }. The method start() has no parameters and no return value.

2

Create the Car struct conforming to Vehicle

Create a struct called Car that conforms to the Vehicle protocol. Add a stored property name of type String.

Swift

protocol Vehicle {
    var name: String { get }
    func start()
}

// Create struct Car conforming to Vehicle with a stored property 'name'
// Your code here

Need a hint?

Use struct Car: Vehicle to conform. The name property can be a constant let. Implement the start() method inside the struct.

3

Implement the start() method

Inside the Car struct, implement the start() method to print the message: " is starting" where is the car's name.

Swift

protocol Vehicle {
    var name: String { get }
    func start()
}

struct Car: Vehicle {
    let name: String
    // Implement start() method here
    // Your code here
}

Need a hint?

Use print with string interpolation to include the name property in the message.

4

Create a Car instance and call start()

Create a constant myCar of type Car with the name "Tesla". Then print myCar.name and call myCar.start().

Swift

protocol Vehicle {
    var name: String { get }
    func start()
}

struct Car: Vehicle {
    let name: String
    func start() {
        print("\(name) is starting")
    }
}

// Create a Car instance named myCar with name "Tesla"
// Print myCar.name and call myCar.start()
// Your code here

Need a hint?

Create myCar with Car(name: "Tesla"). Use print(myCar.name) and myCar.start() to show the output.