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
}
xxxxxxxxxx
 
val text = "a1b2c3d4e5"
val textWithOnlyDigits = text.filter { it.isDigit() }
println(textWithOnlyDigits) // 12345 
Open in Playground →
Target: JVMRunning on v.2.1.20

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
}
xxxxxxxxxx
 
val text = "a1b2c3d4e5"
val textWithOnlyDigits = text.filter { it.isDigit() }
println(textWithOnlyDigits) // 12345 
Open in Playground →
Target: JVMRunning on v.2.1.20

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