isDigit

Common
JVM
JS
Native
1.0
fun Char.isDigit(): Boolean

Returns true if this character is a digit.

A character is considered to be a digit if its category is CharCategory.DECIMAL_DIGIT_NUMBER.

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

fun main(args: Array<String>) {
//sampleStart
val chars = listOf('a', '+', '1')
val (digits, notDigits) = chars.partition { it.isDigit() }
println(digits) // [1]
println(notDigits) // [a, +]
//sampleEnd
}