filter

Common

JVM

Native

1.0

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.

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

fun main(args: Array<String>) {
//sampleStart
val text = "a1b2c3d4e5"

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

println(textWithOnlyDigits) // 12345
//sampleEnd
}

Common

JVM

Native

1.0

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.

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

fun main(args: Array<String>) {
//sampleStart
val text = "a1b2c3d4e5"

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

println(textWithOnlyDigits) // 12345
//sampleEnd
}