Custom getters and setters in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a custom getter that returns the name in uppercase.

Kotlin

class Person(val name: String) {
    val upperName: String
        get() = [1]
}

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

Aname.lowercase()

Bname.uppercase()

Cname.length

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase() instead of uppercase()

Returning the original name without conversion

The custom getter returns the name in uppercase using uppercase().

2fill in blank

medium

Complete the code to define a custom setter that sets the age only if it is positive.

Kotlin

class Person {
    var age: Int = 0
        set(value) {
            if ([1]) field = value
        }
}

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

Avalue > 0

Bvalue < 0

Cvalue == 0

Dvalue >= 0

Attempts:

3 left

💡 Hint

Common Mistakes

Using value < 0 which allows negative ages

Using value >= 0 which allows zero age

The setter checks if the new value is greater than zero before setting it.

3fill in blank

hard

Fix the error in the custom setter to avoid infinite recursion.

Kotlin

class Rectangle {
    var width: Int = 0
        set(value) {
            [1] = value
        }
}

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

Afield

Bwidth

Cthis.width

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Assigning to the property name instead of field

Using this.width which also calls the setter

Use field inside the setter to assign the backing field and avoid recursion.

4fill in blank

hard

Fill both blanks to create a custom getter that returns the area of the rectangle.

Kotlin

class Rectangle(val height: Int, val width: Int) {
    val area: Int
        get() = [1] * [2]
}

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

Aheight

Bwidth

Carea

Dthis

Attempts:

3 left

💡 Hint

Common Mistakes

Using area inside its own getter causing recursion

Using this which is not a number

The getter multiplies height and width to calculate the area.

5fill in blank

hard

Fill all three blanks to create a property with a custom getter and setter that keeps the score between 0 and 100.

Kotlin

class Game {
    var score: Int = 0
        get() = [1]
        set(value) {
            field = when {
                value < 0 -> [2]
                value > 100 -> [3]
                else -> value
            }
        }
}

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

Afield

B0

C100

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Getter returning value instead of field

Setter not clamping values correctly

The getter returns the backing field. The setter clamps the score between 0 and 100.