Kotlin Map minOf()
Syntax & Examples

Syntax of Map.minOf()

The syntax of Map.minOf() extension function is:

fun <K, V> Map<out K, V>.minOf( selector: (Entry<K, V>) -> Double ): Double

This minOf() extension function of Map returns the smallest value among all values produced by selector function applied to each entry in the map.

✐ Examples

1 Get smallest value in the map

In this example,

We create a map named map1 with key-value pairs.
We use the minOf() function on map1 with a selector based on values converted to Double.
The resulting value is the smallest among all values in map1.
We print the resulting value to standard output.

Kotlin Program

fun main(args: Array<String>) {
    val map1 = mapOf("key1" to 1, "key2" to 2, "key3" to 3)
    val result = map1.minOf { it.value.toDouble() }
    println(result)
}

Output

1.0

2 Get smallest key length as Double in the map

In this example,

We create a map named map2 with key-value pairs.
We use the minOf() function on map2 with a selector based on key lengths converted to Double.
The resulting value is the smallest key length as Double in map2.
We print the resulting value to standard output.

Kotlin Program

fun main(args: Array<String>) {
    val map2 = mapOf("apple" to 1, "banana" to 2, "cherry" to 3)
    val result = map2.minOf { it.key.length.toDouble() }
    println(result)
}

Output

5.0

3 Get smallest key length as Double in the map

In this example,

We create a map named map3 with key-value pairs.
We use the minOf() function on map3 with a selector based on key lengths converted to Double.
The resulting value is the smallest key length as Double in map3.
We print the resulting value to standard output.

Kotlin Program

fun main(args: Array<String>) {
    val map3 = mapOf("one" to 1, "two" to 2, "three" to 3)
    val result = map3.minOf { it.key.length.toDouble() }
    println(result)
}

Output

3.0

Summary

In this Kotlin tutorial, we learned about minOf() extension function of Map: the syntax and few working examples with output and detailed explanation for each example.