kotlin-stdlib/kotlin.collections/partition

partition

inline fun <T> Array<out T>.partition(predicate: (T) -> Boolean): Pair<List<T>, List<T>>(source)
inline fun ByteArray.partition(predicate: (Byte) -> Boolean): Pair<List<Byte>, List<Byte>>(source)
inline fun ShortArray.partition(predicate: (Short) -> Boolean): Pair<List<Short>, List<Short>>(source)
inline fun IntArray.partition(predicate: (Int) -> Boolean): Pair<List<Int>, List<Int>>(source)
inline fun LongArray.partition(predicate: (Long) -> Boolean): Pair<List<Long>, List<Long>>(source)
inline fun FloatArray.partition(predicate: (Float) -> Boolean): Pair<List<Float>, List<Float>>(source)
inline fun DoubleArray.partition(predicate: (Double) -> Boolean): Pair<List<Double>, List<Double>>(source)
inline fun BooleanArray.partition(predicate: (Boolean) -> Boolean): Pair<List<Boolean>, List<Boolean>>(source)
inline fun CharArray.partition(predicate: (Char) -> Boolean): Pair<List<Char>, List<Char>>(source)

Splits the original array into a pair of lists, where first list contains elements for which predicate yielded true, while second list contains elements for which predicate yielded false.

Since Kotlin

1.0

Samples

import kotlin.test.*

fun main() { 
   //sampleStart 
   val array = intArrayOf(1, 2, 3, 4, 5)
val (even, odd) = array.partition { it % 2 == 0 }
println(even) // [2, 4]
println(odd) // [1, 3, 5] 
   //sampleEnd
}
inline fun <T> Iterable<T>.partition(predicate: (T) -> Boolean): Pair<List<T>, List<T>>(source)

Splits the original collection into a pair of lists, where first list contains elements for which predicate yielded true, while second list contains elements for which predicate yielded false.

Since Kotlin

1.0

Samples


fun main() { 
   //sampleStart 
   data class Person(val name: String, val age: Int) {
    override fun toString(): String {
        return "$name - $age"
    }
}

val list = listOf(Person("Tom", 18), Person("Andy", 32), Person("Sarah", 22))
val result = list.partition { it.age < 30 }
println(result) // ([Tom - 18, Sarah - 22], [Andy - 32]) 
   //sampleEnd
}