Check if an array contains a specific value in Kotlin

This article explores different ways to check whether an array contains the specified value or not in Kotlin.

1. Using `contains()` function

The utility function to check the presence of an element in an array is with the contains() function.

fun <T> isPresent(arr: Array<T>, target: T): Boolean {

return arr.contains(target)

}

fun main() {

var arr = arrayOf(4, 7, 3, 5, 2)

val key = 5

println(isPresent(arr, key)) // true

}

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2. Using ‘In’ operator

Kotlin provides an In operator, which is an alternative syntax for contains.

fun <T> isPresent(arr: Array<T>, target: T): Boolean {

return target in arr

}

fun main() {

var arr = arrayOf(4, 7, 3, 5, 2)

val key = 5

println(isPresent(arr, key)) // true

}

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3. Using `indexOf()` function

Alternatively, you can use the indexOf() function as follows:

fun <T> isPresent(arr: Array<T>, target: T): Boolean {

return arr.indexOf(target) >= 0

}

fun main() {

var arr = arrayOf(4, 7, 3, 5, 2)

val key = 5

println(isPresent(arr, key)) // true

}

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4. Using `any()` function

Another plausible way is to use the any() function, which returns true if at least one element in the array matches the given predicate.

fun <T> isPresent(arr: Array<T>, target: T): Boolean {

return arr.any{ i -> i == target }

}

fun main() {

var arr = arrayOf(4, 7, 3, 5, 2)

val key = 5

println(isPresent(arr, key)) // true

}

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5. Using `filter()` function

You can also use the filter() function to check if an array contains a specified value, as shown below:

fun <T> isPresent(arr: Array<T>, target: T): Boolean {

return arr.filter { x: T -> x == target }

.count() > 0

}

fun main() {

var arr = arrayOf(4, 7, 3, 5, 2)

val key = 5

println(isPresent(arr, key)) // true

}

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6. Linear search

You can also perform a linear search on the given array to check for the specified value in the array.

fun <T> isPresent(arr: Array<T>, target: T): Boolean {

for (s in arr)

{

if (target == s) {

return true

}

return false

}

fun main() {

var arr = arrayOf(4, 7, 3, 5, 2)

val key = 5

println(isPresent(arr, key)) // true

}

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That’s all about determining whether an array contains a specific value in Kotlin.

Check if an array contains a specific value in Kotlin

1. Using contains() function

2. Using ‘In’ operator

3. Using indexOf() function

4. Using any() function

5. Using filter() function

6. Linear search

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1. Using `contains()` function

3. Using `indexOf()` function

4. Using `any()` function

5. Using `filter()` function