Calling super for parent behavior in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to call the parent class's method inside the child class method.

Swift

class Parent {
    func greet() {
        print("Hello from Parent")
    }
}

class Child: Parent {
    override func greet() {
        [1].greet()
        print("Hello from Child")
    }
}

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

Aself

Bsuper

CParent

DChild

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'self' instead of 'super' to call the parent method.

Calling the method without 'super' leading to recursive calls.

In Swift, to call the parent class's method from an overridden method, use 'super.methodName()'.

2fill in blank

medium

Complete the code to ensure the parent class initializer is called inside the child class initializer.

Swift

class Vehicle {
    var wheels: Int
    init(wheels: Int) {
        self.wheels = wheels
    }
}

class Car: Vehicle {
    var brand: String
    init(brand: String) {
        self.brand = brand
        [1].init(wheels: 4)
    }
}

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

Asuper

BCar

CVehicle

Dself

Attempts:

3 left

💡 Hint

Common Mistakes

Calling 'self.init' instead of 'super.init' causing infinite recursion.

Not calling the parent initializer leading to compile errors.

In Swift, the child class must call the parent class initializer using 'super.init(...)' to properly initialize inherited properties.

3fill in blank

hard

Fix the error in the code by correctly calling the parent class's method inside the overridden method.

Swift

class Animal {
    func sound() {
        print("Animal sound")
    }
}

class Dog: Animal {
    override func sound() {
        [1].sound()
        print("Bark")
    }
}

let dog = Dog()
dog.sound()

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

Aself

BAnimal

Csuper

DDog

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'self' instead of 'super' causing recursive calls.

Calling the method on the class name instead of using 'super'.

To call the parent class's method inside an overridden method, use 'super.methodName()' in Swift.

4fill in blank

hard

Fill both blanks to correctly override the method and call the parent class's method.

Swift

class Printer {
    func printMessage() {
        print("Printing from Printer")
    }
}

class ColorPrinter: Printer {
    override func printMessage() {
        [1].printMessage()
        print("Printing in color")
    }
}

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

Asuper

Bself

CPrinter

DColorPrinter

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'self' instead of 'super' causing recursion.

Using the child class name instead of the parent class name.

Use 'super' to call the parent method.

5fill in blank

hard

Fill all three blanks to override the initializer and call the parent initializer correctly.

Swift

class Device {
    var model: String
    init(model: String) {
        self.model = model
    }
}

class Phone: Device {
    var os: String
    init(model: String, os: String) {
        self.os = [1]
        [2].init(model: [3])
    }
}

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

Aos

Bsuper

Cmodel

Dself

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'self' instead of 'super' to call the parent initializer.

Assigning wrong variables to properties.

Not calling the parent initializer causing errors.

Assign the parameter 'os' to the property, then call the parent initializer with 'super.init(model: model)'.