Split a string on newline in Kotlin

This article explores different ways to split a string on newline in Kotlin.

Different operating systems uses different line terminator wrt each other. For example, Windows uses a carriage-return and line-feed character (\r\n) as a line terminator. Mac uses a carriage-return character (represented as \r) and Unix uses a line-feed character (represented as \n) to mark the end of a line.

The split() function is often used to split a string around matches of a regular expression. To split a string on newlines, we can use the regular expression \r?\n|\r which matches with all different line terminator i.e., \r\n, \r, and \n.

fun main() {

val str = "A\nB\nC"

val lines = str.split("\r?\n|\r".toRegex()).toTypedArray()

println(listOf(*lines)) // [A, B, C]

}

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To skip empty lines, we can change the regular expression to [\r\n]+.

fun main() {

val str = "A\nB\n\n\r\nC"

val lines = str.split("[\r\n]+".toRegex()).toTypedArray()

println(listOf(*lines)) // [A, B, C]

}

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To match with any Unicode linebreak sequence, we can use the linebreak matcher \R.

fun main() {

val str = "A\r\nB\r\nC"

val lines = str.split("\\R".toRegex()).toTypedArray()

println(listOf(*lines)) // [A, B, C]

}

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That’s all about splitting a string on newline in Kotlin.

Split a string on newline in Kotlin

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