Learning Kotlin: Lambdas

Published on 19 June 2018 • Estimated reading time: 1 minutes

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So, following C#, Kotlin has lambda support, with the change of => becoming ->. The koan starts with some nice examples at the start:

fun example() {
    val sum = { x: Int, y: Int -> x + y }
    val square: (Int) -> Int = { x -> x * x }
    sum(1, square(2)) == 5
}

Basically, though, the code that needs to be done is to check a collection if all items are even—which can easily be done with:

fun task4(collection: Collection<Int>): Boolean = collection.all { item -> item % 2 == 0 }