Inline functions and performance in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an inline function in Kotlin.

Kotlin

inline fun [1](block: () -> Unit) {
    block()
}

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

AinlineFun

BrunBlock

Cexecute

DcallBlock

Attempts:

3 left

💡 Hint

Common Mistakes

Using a keyword as a function name.

Leaving the function name blank.

The function name can be anything, but here 'inlineFun' is used as a clear example of an inline function name.

2fill in blank

medium

Complete the code to call the inline function with a lambda expression.

Kotlin

inlineFun {
    println([1])
}

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

A"Hello, Kotlin!"

BHello, Kotlin!

Cprintln

Dlambda

Attempts:

3 left

💡 Hint

Common Mistakes

Passing an unquoted string causing a syntax error.

Passing a function name instead of a string.

The println function expects a string argument, so the string must be in quotes.

3fill in blank

hard

Fix the error in the inline function declaration by completing the code.

Kotlin

inline fun [1](crossinline block: () -> Unit) {
    val runnable = Runnable {
        block()
    }
    runnable.run()
}

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

ArunBlock

BinlineFun

CexecuteBlock

DrunLambda

Attempts:

3 left

💡 Hint

Common Mistakes

Using different function names causing unresolved reference errors.

Omitting the 'inline' keyword.

The function name must match the call site; here 'inlineFun' is the correct name to fix the error.

4fill in blank

hard

Fill both blanks to create a higher-order inline function that accepts a lambda and returns its result.

Kotlin

inline fun <T> [1](block: () -> T): T {
    return block[2]()
}

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

AinlineCall

Binvoke

C()

D.invoke

Attempts:

3 left

💡 Hint

Common Mistakes

Using '()' directly after 'block' without dot notation.

Choosing a function name that is a Kotlin keyword.

The function name 'inlineCall' is chosen, and the lambda is invoked using '.invoke()' syntax.

5fill in blank

hard

Fill all three blanks to create an inline function with a reified type parameter and a lambda that returns a Boolean.

Kotlin

inline fun <reified [1]> [2](predicate: ([3]) -> Boolean): Boolean {
    return predicate.invoke(null as [1])
}

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

AT

BcheckType

DU

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for the type parameter and lambda parameter.

Omitting 'reified' keyword.

The reified type parameter is 'T', the function name is 'checkType', and the lambda parameter type is 'T'.