contains - Kotlin Programming Language

Common

JVM

JS

Native

1.0

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

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

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

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

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

@DeprecatedSinceKotlin("1.4", "1.6") operator fun FloatArray.contains(
    element: Float
): Boolean

(source)

Deprecated: The function has unclear behavior when searching for NaN or zero values and will be removed soon. Use 'any { it == element }' instead to continue using this behavior, or '.asList().contains(element: T)' to get the same search behavior as in a list.

@DeprecatedSinceKotlin("1.4", "1.6") operator fun DoubleArray.contains(
    element: Double
): Boolean

(source)

Deprecated: The function has unclear behavior when searching for NaN or zero values and will be removed soon. Use 'any { it == element }' instead to continue using this behavior, or '.asList().contains(element: T)' to get the same search behavior as in a list.

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

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

Returns true if element is found in the array.

Common

JVM

JS

Native

1.0

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

Returns true if element is found in the collection.

Common

JVM

JS

Native

1.0

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

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.

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

fun main(args: Array<String>) {
//sampleStart
val map: Map<String, Int> = mapOf("x" to 1)

println("map.contains("x") is ${map.contains("x")}") // true
println(""x" in map is ${"x" in map}") // true

println("map.contains("y") is ${map.contains("y")}") // false
println(""y" in map is ${"y" in map}") // false
//sampleEnd
}