kotlin-stdlib/kotlin.text/substringBefore

substringBefore

fun String.substringBefore(delimiter: Char, missingDelimiterValue: String = this): String(source)
fun String.substringBefore(delimiter: String, missingDelimiterValue: String = this): String(source)

Returns a substring before the first occurrence of delimiter. If the string does not contain the delimiter, returns missingDelimiterValue which defaults to the original string.

Since Kotlin

1.0