I have two immutable maps, as example:
val a = mapOf("a" to 1, "z" to 1)
val b = mapOf("b" to 1, "a" to 1, "c" to 1)
Is there any elegant way to concatenate these maps and have a single map with all the keys? If it has duplicated keys, I want to replace it with value from B map.
The result should look something like:
mapOf("z" to 1, "b" to 1, "a" to 1, "c" to 1)
simple + operator:
/**
* Creates a new read-only map by replacing or adding entries to this map from another [map].
*
* The returned map preserves the entry iteration order of the original map.
* Those entries of another [map] that are missing in this map are iterated in the end in the order of that [map].
*/
public operator fun <K, V> Map<out K, V>.plus(map: Map<out K, V>): Map<K, V> =
LinkedHashMap(this).apply { putAll(map) }
example:
fun main(args: Array<String>) {
val a = mapOf("a" to 1, "z" to 1)
val b = mapOf("b" to 1, "a" to 2, "c" to 1)
val c = a+b
println(c)
}