all
Returns true
if all characters match the given predicate.
Note that if the char sequence contains no characters, the function returns true
because there are no characters in it that do not match the predicate.
See a more detailed explanation of this logic concept in "Vacuous truth" article.
import kotlin.test.*
fun main(args: Array<String>) {
//sampleStart
val isEven: (Int) -> Boolean = { it % 2 == 0 }
val zeroToTen = 0..10
println("zeroToTen.all { isEven(it) } is ${zeroToTen.all { isEven(it) }}") // false
println("zeroToTen.all(isEven) is ${zeroToTen.all(isEven)}") // false
val evens = zeroToTen.map { it * 2 }
println("evens.all { isEven(it) } is ${evens.all { isEven(it) }}") // true
val emptyList = emptyList<Int>()
println("emptyList.all { false } is ${emptyList.all { false }}") // true
//sampleEnd
}