https://medium.com/@lawrey/swiftytutorial-map-properties-of-2-arrays-9da34c5e279d

SwiftyTutorial -MapTwoArraysProperty

//: Playground for : https://medium.com/@lawrey/swiftytutorial-map-properties-of-2-arrays-9da34c5e279d

import Foundation

enum CardType {
    case debit
    case credit
}

struct Bank {
    var code: Int
    var name: String
}

struct PaymentMethod {
    var bankCode: Int
    var bankName: String?
    var endingNumber: String
    var cardType: CardType
}

var banks: [Bank]?

banks = [
    Bank(code: 11, name: "DBS"),
    Bank(code: 22, name: "HSBC"),
    Bank(code: 33, name: "OCBC"),
    Bank(code: 44, name: "SC")
]

var paymentMethod1 = PaymentMethod(bankCode: 11, bankName: nil, endingNumber: "1111", cardType: .debit)
var paymentMethod2 = PaymentMethod(bankCode: 22, bankName: nil, endingNumber: "2222", cardType: .debit)
var paymentMethod3 = PaymentMethod(bankCode: 33, bankName: nil, endingNumber: "3333", cardType: .credit)
var paymentMethod4 = PaymentMethod(bankCode: 44, bankName: nil, endingNumber: "4444", cardType: .credit)

var paymentMethods = [
    paymentMethod1,
    paymentMethod2,
    paymentMethod3,
    paymentMethod4,
]

let mappedPaymentMethods = paymentMethods.map { paymentMethod -> PaymentMethod in
    
    guard let banks = banks else {
        return paymentMethod
    }
    
    var mutablePaymentMethod = paymentMethod
    
    if let bank = banks.filter( { $0.code == paymentMethod.bankCode } ).first {
        mutablePaymentMethod.bankName = bank.name
    }
    
    return mutablePaymentMethod
}

mappedPaymentMethods.forEach { (method: PaymentMethod) in print(method) }