018_환율 변동 프로그램
import UIKit import Foundation struct ExchangeRate { var currentcyRate: Double { willSet { print("currencyRate willSet - 환율 변동 예정: \(currentcyRate) -> \(newValue)") } didSet { print("currencyRate didSet - 환율 변동 완료: \(oldValue) -> \(currentcyRate)") } } var USD: Double { willSet { print("USD willSet - 환전 금액: USD: \(newValue)달러로 환전될 예정") } didSet { print("USD didSet - KRW: \(KRW)원 -> \(KRW/current..
2022.07.29