extension_initializer.swift

struct CreditCard {
    var number: String
    var date: String
    var name: String
    var ccv: String
}

extension CreditCard {
    
    init(number: String, date: String, ccv: String) {
        self.number = number
        self.date = date
        self.name = ""
        self.ccv = ccv
    }
    
}

let card = CreditCard(number: "4111 1111 1111 1111", date: "09/12", ccv: "183")
print("\(card)")