kotlinrangecomparable

Creating exclusive ranges in Kotlin

I am just starting with Kotlin. I want to create a range from 1 to n where n is excluded. I found out that Kotlin has ranges and I can use them as follows:

1..n

But this is an inclusive range which includes 1 and n. How do I create exclusive ranges?

Solution

  • Update 2022: Please use the built-in function until.

    Old answer:

    Not sure if this is the best way to do it but you can define an Int extension which creates an IntRange from (lower bound) to (upper bound - 1).

    fun Int.exclusiveRangeTo(other: Int): IntRange = IntRange(this, other - 1)

    And then use it in this way:

    for (i in 1 exclusiveRangeTo n) { //... }

    Here you can find more details about how ranges work.