W3cubDocs

/Kotlin

filter

Platform and version requirements: JVM (1.0), JS (1.0), Native (1.0)

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

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

import kotlin.test.*

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

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

println(textWithOnlyDigits) // 12345
//sampleEnd
}

Platform and version requirements: JVM (1.0), JS (1.0), Native (1.0)

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

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

import kotlin.test.*

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

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

println(textWithOnlyDigits) // 12345
//sampleEnd
}

© 2010–2020 JetBrains s.r.o. and Kotlin Programming Language contributors
Licensed under the Apache License, Version 2.0.
https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.text/filter.html