Merge values in map kotlin

Question

I need merge maps mapA andmapB with pairs of \"name\" - \"phone number\" into the final map, sticking together the values for duplicate keys, separated

Answer 1

In Kotlin you could do this:

fun main() {
    val map1 = mapOf("A" to 1, "B" to 2)
    val map2 = mapOf("A" to 5, "B" to 2)
    val result: Map = listOf(map1, map2)
        .fold(mapOf()) { accMap, map ->
            accMap.merge(map, Int::plus)
        }
    println(result) // Prints: {A=6, B=4}
}

private fun  Map.merge(another: Map, mergeFunction: (V, V) -> V): Map =
    toMutableMap()
        .apply {
            another.forEach { (key, value) ->
                merge(key, value, mergeFunction)
            }
        }