Kotlin Loops in Kotlin Functional constructs for iteration


Example

The Kotlin Standard Library also provides numerous useful functions to iteratively work upon collections.

For example, the map function can be used to transform a list of items.

val numbers = listOf(1, 2, 3, 4, 5, 6, 7, 8, 9, 0)
val numberStrings = numbers.map { "Number $it" }

One of the many advantages of this style is it allows to chain operations in a similar fashion. Only a minor modification would be required if say, the list above were needed to be filtered for even numbers. The filter function can be used.

val numbers = listOf(1, 2, 3, 4, 5, 6, 7, 8, 9, 0)
val numberStrings = numbers.filter { it % 2 == 0 }.map { "Number $it" }