Why is Kotlin String.split with a regex string not the same as Java?

Question

I have the following Java code:

String str = "12+20*/2-4";
List arr = new ArrayList<>();

arr = str.split("\p{Punct}");

//expected: arr = {12,20,2,4}

I want the equivalent Kotlin code, but .split("\p{Punct}") doesn't work. I don't understand the documentation here: https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.text/split.html

user_1809268 · Answer

From Kotlin 1.6 there is a better and easier way of doing this.

fun main() {
    val str = "12+20*/2-4"
    val regex = "\p{Punct}".toRegex()
    var arr = str.splitToSequence(regex);
    arr.forEach(){
            println(it.toString())
    }
}

Reference: https://kotlinlang.org/docs/whatsnew16.html#splitting-regex-into-a-sequence

Why is Kotlin String.split with a regex string not the same as Java?

4 Answers