Multiple interface implementation in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a class that implements two interfaces.

Kotlin

interface A {
    fun foo()
}

interface B {
    fun bar()
}

class MyClass : [1] {
    override fun foo() {
        println("foo")
    }
    override fun bar() {
        println("bar")
    }
}

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

AA & B

BA, B

CA | B

DA B

Attempts:

3 left

💡 Hint

Common Mistakes

Using '&' or '|' instead of ',' to separate interfaces

Not separating interfaces at all

In Kotlin, to implement multiple interfaces, separate them with commas.

2fill in blank

medium

Complete the code to override the method from interface A.

Kotlin

interface A {
    fun greet(): String
}

class Person : A {
    override fun [1](): String {
        return "Hello"
    }
}

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

Ahello

Bgreeting

CsayHello

Dgreet

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different method name than declared in the interface

Forgetting to override the method

The method name must match exactly the one declared in the interface.

3fill in blank

hard

Fix the error in the class declaration to implement both interfaces A and B.

Kotlin

interface A {
    fun foo()
}

interface B {
    fun bar()
}

class Sample : [1] {
    override fun foo() {}
    override fun bar() {}
}

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

AA, B

BA | B

CA & B

DA B

Attempts:

3 left

💡 Hint

Common Mistakes

Using spaces or symbols like '&' or '|' instead of commas

Not separating interfaces

Interfaces must be separated by commas in Kotlin class declarations.

4fill in blank

hard

Fill both blanks to complete the class declaration and method override.

Kotlin

interface X {
    fun action()
}

interface Y {
    fun action()
}

class Combined : [1] {
    override fun [2]() {
        println("Action performed")
    }
}

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

AX, Y

BX & Y

Caction

Dperform

Attempts:

3 left

💡 Hint

Common Mistakes

Using '&' instead of ',' to separate interfaces

Using wrong method name in override

Separate interfaces with commas and override the method named 'action'.

5fill in blank

hard

Fill all three blanks to implement two interfaces and override their methods correctly.

Kotlin

interface First {
    fun firstMethod()
}

interface Second {
    fun secondMethod()
}

class MultiImpl : [1] {
    override fun [2]() {
        println("First method")
    }
    override fun [3]() {
        println("Second method")
    }
}

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

AFirst, Second

BfirstMethod

CsecondMethod

DFirst & Second

Attempts:

3 left

💡 Hint

Common Mistakes

Using '&' instead of ',' to separate interfaces

Incorrect method names in overrides

Separate interfaces with commas and override both methods with their exact names.