What you are trying to do can be achieved by using Dictionaries in swift. It appears that you are not familiar with this topic, so will be of no use to just throw out some code, there are many tutorials about this regard.
Just for mentioning one, (that has even images explaining how it works) you can enter here
Happy Learning & Coding! ;-)
UPDATE:
Here's a playground testing the concept: (Feel free to adjust it to your needs)
var dictionary: [String : [ String ]] = ["" : []]
let storeString = "StoreString"
func addUpdateArray(strings: [String], index: Int) {
let locator = storeString + index.description
dictionary[locator] = strings
}
func getStringWitNameIndex(index:Int) -> [String]? {
return dictionary[ storeString + index.description]
}
func addToArray(index:Int, inout destiny: [String]) {
if let array = getStringWitNameIndex(index) {
destiny = destiny + array
}
}
addUpdateArray(["Hello", "World"], 1)
addUpdateArray(["Hello", "Cats"], 3)
var finalArray : [String] = []
addToArray(1,&finalArray)
addToArray(3,&finalArray)
finalArray
In this case, finalArray ends up having: ["Hello", "World", "Hello",
"Cats"]