Code:#include <iostream.h> void showMenu(); void showFees (double, int); void main() { int choice; int quantity=1; cout<<"\n\n\n"; cout<<" ====== WELCOME TO THE FAST RESTAURANT ORDER SYSTEM!======"; cout<<" \t\t\t ---- Choose your order ----"<<endl<<endl; cout<<" \t 1.Burger TipTop \t 2.Del Chicken"<<endl; cout<<" \t 3.Chicken Fillet \t 4. Spaghetti "<<endl; cout<<" \t 5.Coke \t 6. Apple Pie"<<endl; char cust_name[50]; cout<<"Please Enter Your Name:\t"; cin.getline (cust_name,50); const int BurgerTipTopChoice = 1; const int DelChickenChoice = 2; const int ChickenFilletChoice = 3; const int SpaghettiChoice = 4; const int CokeChoice = 5; const int ApplePieChoice = 6; const int endOrderChoice = 7; const double BurgerTipTop = 6.00; const double DelChicken = 4.50; const double ChickenFillet = 3.75; const double Spaghetti = 5.50; const double Coke = 2.80; const double ApplePie = 3.20; do { showMenu(); cin >> choice; while (choice < BurgerTipTopChoice || choice > endOrderChoice) { cout << "Please enter a valid menu choice: "; cin >> choice; } if (choice != endOrderChoice) { switch (choice) { case BurgerTipTopChoice: showFees(BurgerTipTop, quantity); break; case DelChickenChoice: showFees(DelChicken, quantity); break; case ChickenFilletChoice: showFees(ChickenFillet, quantity); break; case SpaghettiChoice: showFees(Spaghetti, quantity); break; case CokeChoice: showFees(Coke, quantity); break; case ApplePieChoice: showFees(ApplePie, quantity); break; } } } while (choice != endOrderChoice); } void showMenu() { cout << "\n\t\tHere our food available " << endl; cout << "1. Burger TipTop \tRM 6.00"<< endl; cout << "2. Del Chicken \t\tRM 4.50" << endl; cout << "3. Chicken Fillet \tRM 3.75" << endl; cout << "4. Spaghetti \t\tRM 5.50" << endl; cout << "5. Coke \t\tRM 2.80" << endl; cout << "6. Apple Pie \t\tRM 3.20"<< endl; cout << "7. END ORDER" << endl; cout << "Please enter your menu choice: "; } void showFees(double itemCost, int quantity) { double amtcash; double totalBill = (itemCost * quantity); double amountDue=totalBill; cout << "Total Bill: RM" << totalBill << endl; cout << "Total Amount Due: RM" << amountDue << endl; cout << "Enter amount cash: RM"; cin >> amtcash; double change = amtcash - amountDue; cout << "Change : RM" << change << endl; }