Chaining scope functions in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to chain two scope functions on the string.

Kotlin

val result = "hello".[1] {
    println(it.uppercase())
}

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

Aalso

Blet

Capply

Drun

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'let' returns the block result, not the original object.

Using 'apply' changes the context but returns the object, but it expects 'this' as receiver.

The also function returns the original object after applying the block, allowing chaining.

2fill in blank

medium

Complete the code to chain let and run to transform and print a string.

Kotlin

val length = "kotlin".let {
    it.uppercase()
}.[1] {
    println(this)
    this.length
}

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

Arun

Bapply

Cwith

Dalso

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'also' returns the original object, not the block result.

Using 'apply' returns the object, not the block result.

The run function executes the block with this as the context and returns the block result.

3fill in blank

hard

Fix the error in chaining apply and let to modify and print a mutable list.

Kotlin

val list = mutableListOf(1, 2, 3).[1] {
    add(4)
}.let {
    println(it)
    it.size
}

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

Aalso

Bapply

Crun

Dwith

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'also' returns the object but expects 'it' as context, which may confuse modification.

Using 'run' returns the block result, not the object.

apply returns the object after applying changes, allowing let to receive the updated list.

4fill in blank

hard

Fill both blanks to chain let and also to transform and print a string.

Kotlin

val result = "scope".[1] {
    it.uppercase()
}.[2] {
    println(it)
}

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

Alet

Balso

Capply

Drun

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'apply' instead of 'also' changes the context to 'this' which is not expected here.

Using 'run' returns the block result but changes context to 'this'.

let transforms the string and returns the result; also prints it and returns the original object.

5fill in blank

hard

Fill all three blanks to chain apply, let, and also to modify, transform, and print a list.

Kotlin

val size = mutableListOf(5, 6).[1] {
    add(7)
}.[2] {
    it.sum()
}.[3] {
    println(it)
}

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

Aapply

Blet

Calso

Drun

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'run' changes context to 'this' and returns block result, which may confuse the chain.

Mixing 'also' and 'apply' in wrong order breaks the expected return values.

apply modifies the list and returns it; let calculates the sum; also prints the sum and returns it.