How to Iterate Over Values in a Map in Kotlin - Step by Step Examples

How to Iterate Over Values in a Map in Kotlin ?

Answer

To iterate over values in a map in Kotlin, you can use the values property along with a for loop or the forEach method. This allows you to access each value in the map.

✐ Examples

1 Iterating Over Values Using for Loop

We can iterate over values in a map in Kotlin using a for loop with the values property, which provides a convenient syntax for iterating over all values in the map.

For example,

We start by declaring and initializing a map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
We use the values property to get a collection of the values in the map.
We iterate over the values using a for loop, accessing each value directly from the collection.
We print each value to the console using the println function to verify that we are iterating over all values.

Kotlin Program

fun main() {
    // Declare and initialize a map
    val myMap = mapOf(
        "one" to 1,
        "two" to 2,
        "three" to 3
    )

    // Iterate over values using for loop
    for (value in myMap.values) {
        println(value)
    }
}

Output

1
2
3

2 Iterating Over Values Using forEach Method

We can iterate over values in a map in Kotlin using the forEach method, which provides a flexible way to access each value in the map.

For example,

We start by declaring and initializing a map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
We use the forEach method to iterate over the key-value pairs in the map.
In the lambda expression passed to forEach, we access each value.
We print each value to the console using the println function to verify that we are iterating over all values.

Kotlin Program

fun main() {
    // Declare and initialize a map
    val myMap = mapOf(
        "one" to 1,
        "two" to 2,
        "three" to 3
    )

    // Iterate over values using forEach method
    myMap.forEach { (_, value) ->
        println(value)
    }
}

Output

1
2
3

3 Storing and Iterating Over Values Separately

We can store values in a separate list and then iterate over the list in Kotlin, which provides a way to work with values independently of their keys.

For example,

We start by declaring and initializing a map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
We declare a list named values to store the values from the map.
We use the values property to get a collection of the values in the map and convert it to a list using the toList method.
We use a for loop to iterate over the values list and print each value to the console using the println function to verify that we have stored all values separately.

Kotlin Program

fun main() {
    // Declare and initialize a map
    val myMap = mapOf(
        "one" to 1,
        "two" to 2,
        "three" to 3
    )

    // Store values in a separate list
    val values = myMap.values.toList()

    // Iterate over the values list
    for (value in values) {
        println(value)
    }
}

Output

1
2
3

Summary

In this tutorial, we learned How to Iterate Over Values in a Map in Kotlin language with well detailed examples.

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