Check if the element exists in the array, and then replace between two arrays Swift

I have a class "Players", and a class "Team". I created two array of Strings calling player1.name, player2.name, etc.
one array with main players and the other array with secondary players

Class:

class Players {
    let name: String
    let number: int
    var position:PositionPlayer
    var birth: Date
    let nationality: String
    var height: Double 
    var weight: int
    init(name: String, number: Int, position: PositionPlayer, birth: Date, height: Double, weight: Int) {
        self.name = name
        self.number = number
        self.position = position
        self.birth = birth
        self.nationality = nationality
        self.height = height
        self.weight = weight
    }

Class Team is empty (just doing the function on it)

Arrays:

var mainPlayers: [String] = []
var secondaryPlayers: [String] = []

add elements in arrays:

mainPlayers.append("\(player1.name)")

How do I make a function in class "Team" that checks the elements of the arrays and does the substitution between the 2 arrays?

e.g. I have 3 main players and 3 secondary players, and I want to put player 4 (secondary player) in place of player 1.

>Solution :

If the order of the collection doesnt matter you should use a set to make sure there is no duplicated players in your collection:

var mainPlayers: Set = ["player1", "player2", "player3"]
var secondaryPlayers: Set = ["player4", "player5", "player6"]

if let oldMember = mainPlayers.remove("player1"),
    let newMember = secondaryPlayers.remove("player4"),
   mainPlayers.insert(newMember).inserted,
   secondaryPlayers.insert(oldMember).inserted {
    print("oldMember", oldMember)   // player1
    print("newMember", newMember)   // player4
    print(mainPlayers)       // ["player3", "player4", "player2"]
    print(secondaryPlayers)  // ["player1", "player5", "player6"]
}