Programming Kotlin

Range and Iteration

Imagine telling someone to count from one to five by uttering “set i equal to 1 but while keeping i less than 6, increment i and report the value.” If we had to communicate with a fellow human that way, it would have ended civilization a long time ago. Yet that’s how programmers have been writing code in many C-like languages. But we don’t have to, at least not in Kotlin.

Range Classes

Kotlin raises the level of abstraction to iterate over a range of values with specialized classes. For instance, here’s a way to create a range of numbers from 1 to 5.

iteration/ranges.kts

val oneToFive: IntRange = 1..5

The type IntRange, which is part of the kotlin.ranges package, is provided for clarity, but you may leave it out and let ...