How to Check if a Value Exists in a Map in Kotlin

How to Check if a Value Exists in a Map in Kotlin ?

Answer

To check if a value exists in a map in Kotlin, you can use the containsValue method. This method returns a boolean value indicating whether the map contains the specified value.

✐ Examples

1 Checking if a Value Exists Using containsValue Method

We can check if a value exists in a map in Kotlin using the containsValue method, which returns true if the map contains the specified value and false otherwise.

For example,

We start by declaring and initializing a mutable map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
We use the containsValue method to check for a specific value in the map. The containsValue method returns a boolean value indicating whether the map contains the specified value.
We print the result to the console using the println function.

Kotlin Program

fun main() {
    // Declare and initialize a mutable map
    val myMap: MutableMap<String, Int> = mutableMapOf(
        "one" to 1,
        "two" to 2,
        "three" to 3
    )

    // Check if a value exists using containsValue method
    val valueExists = myMap.containsValue(2)

    // Print the result
    println("Does value 2 exist? $valueExists")
}

Output

Does value 2 exist? true

2 Checking if a Value Does Not Exist Using containsValue Method

We can check if a value does not exist in a map in Kotlin using the containsValue method, which returns false if the map does not contain the specified value.

For example,

We start by declaring and initializing a mutable map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
We use the containsValue method to check for a specific value in the map. The containsValue method returns a boolean value indicating whether the map contains the specified value.
We print the result to the console using the println function.

Kotlin Program

fun main() {
    // Declare and initialize a mutable map
    val myMap: MutableMap<String, Int> = mutableMapOf(
        "one" to 1,
        "two" to 2,
        "three" to 3
    )

    // Check if a value does not exist using containsValue method
    val valueExists = myMap.containsValue(4)

    // Print the result
    println("Does value 4 exist? $valueExists")
}

Output

Does value 4 exist? false

3 Checking Multiple Values Using containsValue Method

We can check if multiple values exist in a map in Kotlin using the containsValue method, which returns true if the map contains the specified value and false otherwise.

For example,

We start by declaring and initializing a mutable map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
We use the containsValue method to check for multiple values in the map. The containsValue method returns a boolean value indicating whether the map contains the specified value.
We print the results to the console using the println function.

Kotlin Program

fun main() {
    // Declare and initialize a mutable map
    val myMap: MutableMap<String, Int> = mutableMapOf(
        "one" to 1,
        "two" to 2,
        "three" to 3
    )

    // Check if multiple values exist using containsValue method
    val valueExistsOne = myMap.containsValue(1)
    val valueExistsFour = myMap.containsValue(4)

    // Print the results
    println("Does value 1 exist? $valueExistsOne")
    println("Does value 4 exist? $valueExistsFour")
}

Output

Does value 1 exist? true
Does value 4 exist? false

Summary

In this tutorial, we learned How to Check if a Value Exists in a Map in Kotlin language with well detailed examples.

◀ Previous Next ▶

Kotlin Tutorials

Kotlin How-Tos

How to Check if a Value Exists in a Map in Kotlin