kotlin-stdlib/kotlin.text/filter

filter

inline fun CharSequence.filter(predicate: (Char) -> Boolean): CharSequence(source)

Returns a char sequence containing only those characters from the original char sequence that match the given predicate.

Since Kotlin

1.0

Samples

import java.util.Locale
import kotlin.test.*

fun main() { 
   //sampleStart 
   val text = "a1b2c3d4e5"

val textWithOnlyDigits = text.filter { it.isDigit() }

println(textWithOnlyDigits) // 12345 
   //sampleEnd
}
inline fun String.filter(predicate: (Char) -> Boolean): String(source)

Returns a string containing only those characters from the original string that match the given predicate.

Since Kotlin

1.0

Samples

import java.util.Locale
import kotlin.test.*

fun main() { 
   //sampleStart 
   val text = "a1b2c3d4e5"

val textWithOnlyDigits = text.filter { it.isDigit() }

println(textWithOnlyDigits) // 12345 
   //sampleEnd
}