I need to make a built-in counter of the number of things through the Map in the Map.

initialization:

var Items = mapOf<Map<String, Item>, Int>()

Example of interaction

for(i in item)
    if (this.UnitInventory.Items.containsKey(Pair(i.Name, i) as Map<String, Item>))
        this.UnitInventory.Items[Pair(i.Name, i)]  
    else
        this.UnitInventory.Items  = mapOf(Pair(Pair(i.Name, i) as Map<String, Item>, 1))

How to properly write part this.UnitInventory.Items[Pair(i.Name, i)] ?

CodePudding user response：

Like Tenfour04 says in the comments, this is kinda brittle - but so long as you're using immutable Maps as keys it's probably ok? Anyway, if that's what you want, you can do this:

// this -outer- map needs to be mutable (since you'll be adding new counts)
val items = mutableMapOf<Map<String, Int>, Int>()

// make some map keys to count
val someMap = mapOf("One" to 1)
val someOtherMap = mapOf("Two" to 2, "Three" to 3)
val stuff = listOf(someMap, someOtherMap, someMap)

// add them to the counts
stuff.forEach { item ->
    // update the current count, defaulting to zero if it doesn't exist yet
    items[item] = items.getOrDefault(item, 0)   1
}
println(items)

>> {{One=1}=2, {Two=2, Three=3}=1}