프로그램 언어의 구조화

var customerCash = 20000
var customerTicket = 0

var sellerCash = 0
var sellerTicket = 5
let ticketPrice = 10000

func canAfford() {
if customerCash >= ticketPrice {
sellTicket()
} else {
refuse()
}
}

func sellTicket() {
customerCash -= ticketPrice
sellerCash += ticketPrice

customerTicket += 1
sellerTicket -= 1

print("즐거운 관람 되세요!")

}

func refuse() {
print("돈이 부족하시네요.")
return
}