Overriding methods with override in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to correctly override the method in Kotlin.

Kotlin

open class Animal {
    open fun sound() {
        println("Animal sound")
    }
}

class Dog : Animal() {
    [1] fun sound() {
        println("Bark")
    }
}

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

Aopen

Boverride

Cfinal

Dabstract

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to use 'override' keyword causes a compilation error.

Using 'open' instead of 'override' when overriding.

In Kotlin, to override a method from a superclass, you must use the 'override' keyword before the function.

2fill in blank

medium

Complete the code to override the method and call the superclass method inside it.

Kotlin

open class Vehicle {
    open fun start() {
        println("Vehicle started")
    }
}

class Car : Vehicle() {
    [1] fun start() {
        super.start()
        println("Car started")
    }
}

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

Aoverride

Bfinal

Copen

Dabstract

Attempts:

3 left

💡 Hint

Common Mistakes

Not using 'override' keyword when overriding.

Trying to override a method without 'open' in superclass.

The 'override' keyword is needed to override a method, and you can call the superclass method using 'super.methodName()'.

3fill in blank

hard

Fix the error by correctly overriding the method in the subclass.

Kotlin

open class Printer {
    open fun printMessage() {
        println("Printing message")
    }
}

class ColorPrinter : Printer() {
    [1] fun printMessage() {
        println("Printing in color")
    }
}

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

Aopen

Bfinal

Cabstract

Doverride

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the 'override' keyword causes the method to be treated as a new method.

Trying to override without 'open' in superclass method.

To override the method from the superclass, the subclass method must have the 'override' keyword.

4fill in blank

hard

Fill both blanks to override the method and call the superclass method inside it.

Kotlin

open class Appliance {
    open fun turnOn() {
        println("Appliance is on")
    }
}

class Fan : Appliance() {
    [1] fun turnOn() {
        [2].turnOn()
        println("Fan is spinning")
    }
}

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

Aoverride

Bsuper

Copen

Dfinal

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting 'override' keyword.

Not calling the superclass method with 'super'.

Use 'override' to override the method and 'super' to call the superclass method.

5fill in blank

hard

Fill all three blanks to override a method, call the superclass method, and add extra behavior.

Kotlin

open class Computer {
    open fun boot() {
        println("Computer booting")
    }
}

class Laptop : Computer() {
    [1] fun boot() {
        [2].boot()
        println([3])
    }
}

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

Aoverride

Bsuper

C"Laptop ready to use"

D"Booting laptop"

Attempts:

3 left

💡 Hint

Common Mistakes

Not using 'override' keyword.

Forgetting to call the superclass method.

Using incorrect string message.

Use 'override' to override, 'super' to call the superclass method, and add a custom message string.