Overriding methods and properties in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to override the method describe() in the subclass.

Swift

class Animal {
    func describe() {
        print("I am an animal.")
    }
}

class Dog: Animal {
    override func [1]() {
        print("I am a dog.")
    }
}

Drag options to blanks, or click blank then click option'

Adescription

Bdescribe

CdescribeAnimal

DprintDescription

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different method name so the method is not actually overridden.

Forgetting the override keyword.

The method describe() is overridden by using the exact same method name with the override keyword.

2fill in blank

medium

Complete the code to override the computed property description in the subclass.

Swift

class Vehicle {
    var description: String {
        return "A vehicle"
    }
}

class Car: Vehicle {
    override var [1]: String {
        return "A car"
    }
}

Drag options to blanks, or click blank then click option'

Adescription

Bdesc

Cinfo

Ddetails

Attempts:

3 left

💡 Hint

Common Mistakes

Changing the property name so it does not override.

Not using the override keyword.

The property description is overridden by using the exact same property name with the override keyword.

3fill in blank

hard

Fix the error in the code by correctly overriding the method makeSound().

Swift

class Bird {
    func makeSound() {
        print("Chirp")
    }
}

class Parrot: Bird {
    override func [1]() {
        print("Squawk")
    }
}

Drag options to blanks, or click blank then click option'

AmakeSound

BmakeNoise

Csound

Dspeak

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different method name so it does not override.

Omitting the override keyword.

The method makeSound() is overridden by using the exact same method name with the override keyword.

4fill in blank

hard

Fill both blanks to override the property speed with a getter and setter.

Swift

class Machine {
    var speed: Int = 0
}

class Car: Machine {
    override var [1]: Int {
        get {
            return super.[2]
        }
        set {
            super.speed = newValue
        }
    }
}

Drag options to blanks, or click blank then click option'

Aspeed

Bvelocity

Dpower

Attempts:

3 left

💡 Hint

Common Mistakes

Using different property names in the override and super access.

Forgetting the override keyword.

The property name must be speed in both places to correctly override the property and access the superclass property.

5fill in blank

hard

Fill both blanks to override a method with parameters and call the superclass method inside.

Swift

class Printer {
    func printMessage(_ message: String) {
        print("Printer: \(message)")
    }
}

class ColorPrinter: Printer {
    override func [1](_ message: String) {
        print("ColorPrinter:")
        super.[2](message)
        print("Done printing.")
    }
}

Drag options to blanks, or click blank then click option'

AprintMessage

CprintMsg

Dprint

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different method name so it does not override.

Not calling the superclass method correctly.

The method name must be printMessage to override correctly and call the superclass method with super.printMessage(message).