Question

Let's fix the displayMenu() method!

First, edit the method to do the following:

1. We want to also allow the user to quit. Include a "Quit" option in the print statements!
2. Have it get the user input from within the method itself and return an int based on the user's choice. (Make sure to also edit the method header and how it is called back in the main() method!)
   What is the method's return type now?                            [ Select ]                       ["int", "double", "String"]      
3. Include input validation for the user's choice before returning the value. For example, if the user enters something that is not an option (such as a 10), tell them to choose again. Keep asking them to enter a number until the input is valid. Only return an integer that is a valid option.
   What will you use to create this input validation?                            [ Select ]                       ["if-statement", "loop"]      

Back in the main() method, add a loop now as well! The user should be able to keep choosing options until they decide to quit. Only stop iterating once they've chosen the option to quit.

Display a goodbye message at the end of the program.

My code is below;

import java.util.Scanner;

public class CoffeeShop {

   public static void main(String[] args) {

Scanner scan = new Scanner(System.in);

int mainMenuChoice = 0;

System.out.println("Welcome to the coffee shop!");

double total = 0.0;

do{

   displayMainMenu();

   mainMenuChoice = scan.nextInt();

   char selection;

   switch(mainMenuChoice){

case 1:

   coffeeSubmenu();

   selection = scan.next().charAt(0);

   total += calculateCoffeePrice(selection);

   break;

case 2:

pastrySubmenu();

selection =scan.next().charAt(0);

   total += calculatePastryPrice(selection);

   break;

case 3:

sodaSubmenu();

selection = scan.next().charAt(0);

   total += calculateSodePrice(selection);

   break;

case 4:

break;

   }

}while(mainMenuChoice != 4);

System.out.println("Total: $" + total);

   }

   private static double calculatePastryPrice(char selection) {

double price = 0.0;

if(selection == 'A'){

price = 4.99;

} else if (selection == 'B'){

price = 2.49;

}

return price;

}

   private static double calculateSodePrice(char selection) {

double price = 0.0;

if(selection == 'A'){

price = 2.99;

} else if (selection == 'B'){

price = 2.49;

}

return price;

}

   public static double calculateCoffeePrice(char selection) {

double price = 0.0;

if(selection == 'A'){

   price = 2.99;

} else if (selection == 'B'){

   price = 3.99;

}

return price;

   }

   public static void displayMainMenu() {

System.out.println("Please select the item type.");

System.out.println("1. Coffee");

System.out.println("2. Pastry");

System.out.println("3. Soda");

System.out.println("4. Quit");

   }

   public static void coffeeSubmenu() {

System.out.println("Please select the coffee.");

System.out.println("A. Drip Coffee");

System.out.println("B. Latte");

   }

   public static void pastrySubmenu() {

System.out.println("Please select the pastry.");

System.out.println("A. Croissant");

System.out.println("B. Muffin");

   }

   public static void sodaSubmenu() {

System.out.println("Please select a soda.");

System.out.println("A. Coca-Cola");

System.out.println("B. Pepsi");

   }

}

Answer 1

Note: Could you plz go through this code and let me know if u need any changes in this.Thank You
=================================

// CoffeeShop.java

import java.util.Scanner;

public class CoffeeShop {
   static Scanner scan = new Scanner(System.in);
   public static void main(String[] args) {

       char selection;

       int mainMenuChoice = 0;

       System.out.println("Welcome to the coffee shop!");

       double total = 0.0;

       do {

          
           mainMenuChoice=displayMainMenu();

      

           switch (mainMenuChoice) {

           case 1:

               selection=coffeeSubmenu();

                 

               total += calculateCoffeePrice(selection);

               break;

           case 2:

               selection=pastrySubmenu();

               total += calculatePastryPrice(selection);

               break;

           case 3:

               selection =sodaSubmenu();

               total += calculateSodePrice(selection);

               break;

           case 4:

               break;
          
           }
          
          

       } while (mainMenuChoice != 4);

       System.out.println("Total: $" + total);
      
       System.out.println("\nGood Bye!");

   }

   private static double calculatePastryPrice(char selection) {

       double price = 0.0;

       if (selection == 'A') {

           price = 4.99;

       } else if (selection == 'B') {

           price = 2.49;

       }

       return price;

   }

   private static double calculateSodePrice(char selection) {

       double price = 0.0;

       if (selection == 'A') {

           price = 2.99;

       } else if (selection == 'B') {

           price = 2.49;

       }

       return price;

   }

   public static double calculateCoffeePrice(char selection) {

       double price = 0.0;

       if (selection == 'A') {

           price = 2.99;

       } else if (selection == 'B') {

           price = 3.99;

       }

       return price;

   }

   public static int displayMainMenu() {

       int choice;
       while(true)
       {
           System.out.println("Please select the item type.");

           System.out.println("1. Coffee");

           System.out.println("2. Pastry");

           System.out.println("3. Soda");

           System.out.println("4. Quit");
           System.out.print("Enter Choice :");
           choice=scan.nextInt();
           if(choice<1 || choice>4)
           {
               System.out.println("** Invalid Choice **");
           }
           else
               break;
       }
      
       return choice;
  

   }

   public static char coffeeSubmenu() {

       char ch;
   while(true)
   {
       System.out.println("\nPlease select the coffee.");

           System.out.println("A. Drip Coffee");

           System.out.println("B. Latte");
           System.out.print("Enter Choice :");
           ch=scan.next().charAt(0);
          
           if(ch=='A' || ch=='a' || ch=='B' || ch=='b')
           {
               break;
           }
           else
           {
               System.out.println("** Invalid Choice **");
           }
   }
   return ch;
  

   }

   public static char pastrySubmenu() {

       char ch;
   while(true)
   {
       System.out.println("\nPlease select the pastry.");

       System.out.println("A. Croissant");

       System.out.println("B. Muffin");
       System.out.print("Enter Choice :");
       ch=scan.next().charAt(0);
       if(ch=='A' || ch=='a' || ch=='B' || ch=='b')
       {
           break;
       }
       else
       {
           System.out.println("** Invalid Choice **");
       }
}
return ch;

   }

   public static char sodaSubmenu() {
       char ch;
   while(true)
   {
       System.out.println("\nPlease select a soda.");

       System.out.println("A. Coca-Cola");

       System.out.println("B. Pepsi");
       System.out.print("Enter Choice :");
       ch=scan.next().charAt(0);
       if(ch=='A' || ch=='a' || ch=='B' || ch=='b')
       {
           break;
       }
       else
       {
           System.out.println("** Invalid Choice **");
       }
}
return ch;
   }

}

==============================

Output:

Welcome to the coffee shop!
Please select the item type.
1. Coffee
2. Pastry
3. Soda
4. Quit
Enter Choice :1

Please select the coffee.
A. Drip Coffee
B. Latte
Enter Choice :D
** Invalid Choice **

Please select the coffee.
A. Drip Coffee
B. Latte
Enter Choice :A
Please select the item type.
1. Coffee
2. Pastry
3. Soda
4. Quit
Enter Choice :5
** Invalid Choice **
Please select the item type.
1. Coffee
2. Pastry
3. Soda
4. Quit
Enter Choice :2

Please select the pastry.
A. Croissant
B. Muffin
Enter Choice :B
Please select the item type.
1. Coffee
2. Pastry
3. Soda
4. Quit
Enter Choice :3

Please select a soda.
A. Coca-Cola
B. Pepsi
Enter Choice :A
Please select the item type.
1. Coffee
2. Pastry
3. Soda
4. Quit
Enter Choice :4
Total: $8.47

Good Bye!

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