kotlin-stdlib/kotlin.collections/contains

contains

operator fun <T> Array<out T>.contains(element: T): Boolean

operator fun ByteArray.contains(element: Byte): Boolean

operator fun ShortArray.contains(element: Short): Boolean

operator fun IntArray.contains(element: Int): Boolean

operator fun LongArray.contains(element: Long): Boolean

@DeprecatedSinceKotlin(warningSince = "1.4")

~~operator~~ ~~fun~~ FloatArray.~~contains~~(~~element~~: Float): Boolean

@DeprecatedSinceKotlin(warningSince = "1.4")

~~operator~~ ~~fun~~ DoubleArray.~~contains~~(~~element~~: Double): Boolean

operator fun BooleanArray.contains(element: Boolean): Boolean

operator fun CharArray.contains(element: Char): Boolean

Returns true if element is found in the array.

operator fun <T> Iterable<T>.contains(element: T): Boolean

Returns true if element is found in the collection.

inline operator fun <K, V> Map<out K, V>.contains(key: K): Boolean

Checks if the map contains the given key.

This method allows to use the x in map syntax for checking whether an object is contained in the map.

Samples

import samples.*
import kotlin.test.*
import java.util.*
fun main() { 
   //sampleStart 
   val map: Map<String, Int> = mapOf("x" to 1)

assertTrue(map.contains("x"))
assertTrue("x" in map)

assertFalse(map.contains("y"))
assertFalse("y" in map) 
   //sampleEnd
}