looped menu

[paulio macmurray]

Hi,

The following code works, but after an action is complete the program ends, but i dont want it to do that, i want the user to be returned to the menu.

Im fairly new with it, and im pretty sure i need a while loop, but i have no idea how to impliment it.

Here is my code so far

import java.util.Scanner;

public class Menu {

    public static void main(String[]arguments)
    {
        
       System.out.println("Welcome to the Booking System");
       System.out.println("Please make a selection");
       System.out.println(" ");
       System.out.println("(1) to add a book   -   (2) to add a new customer   -   (3) to return a book   -   (4) for new loan");

       Scanner scan = new Scanner(System.in);
       System.out.println(">");
       int selection = scan.nextInt();

       if (selection == 1) {
           System.out.println("New Book........");

           Scanner myScanner = new Scanner( System.in );

           System.out.println("Book Name:");

           String BookTitle = myScanner.nextLine();


           System.out.println("Book Author: ");
           String BookAuthor = myScanner.nextLine();


           System.out.println("Book Category: ");
            String BookCategory = myScanner.nextLine();

           Book newBook = new Book(BookTitle, BookAuthor, BookCategory);


       } else {
           if (selection ==2) {
               System.out.println("New Customer........");

           } else {
               if (selection == 3) {
                   System.out.println("Return book........");
               } else {
                   if (selection == 4) {
                       System.out.println("New loan.........");
                   } else {
                       System.out.println("There has been an error......goodbye");
                   }
               }
           }
       }
    }
} 

[Jeanne Boyarsky]

Moving to Java In General since this isn't a JDBC question.

[Jeanne Boyarsky]

Paulio,
A "do-while" loop is traditionally used for this purpose. Can you identify which parts of the code you want to run again? That's the body of the loop. And how do you know you are done? (you probably want another option for "quit" so this doesn't go on forever)

[paulio macmurray]

Hi Thanks for the response.

The pseudo code i wrote was.

1. user selects menu item (eg add book) (which i have)
2. the user inputs data requested via scanner class (which i have)
3. the data is displayed and user asked if they wish to submit.(which i have)
4. If yes, the data is stored (which i have) and the user is returned to the menu (which im stuck with)
5. If no, the user is returned to the menu (which im stuck with)

I agree that i need an exit button, which i have since found, but my brains given up on me

[Janeice DelVecchio]

You're going to need a Do/While statement like another rancher said.... it'll look like this:

 do 
stuff to do here
give the user some chance to exit with a menu or something
set a variable to "false" when the user wants to exit (this variable needs to be initialized before the "do" as true)
while that variable equal to true   

so the do before the while causes the loop to be done at least once. The user choice will let the JVM know if the user wants to exit. You could also ask the user if s/he'd like to keep going and reverse the logic if you like it that way....

Hope that helps

[avijit majumder]

int choice=0;
while(true)
{
System.out.println("\n press 1 for ... , 2 for .... 3for .... , 4 for EXIT");
choice=Integer.parseInt(br.readLine());
switch (choice)
{
case 1://do somthing...call a method...break;
case 2://..... berak;
case 3://...do some thing break;
case 3: system.exit(1);// or break;
defaule: System.out.println("\n Wrong Key Press TRy Again!");
}
}//end while

[paulio macmurray]

Hi all,

I have the following so far, but could do with some help to get the syntax correct.

public class whileDoTest {

    public static void main (String[]arguments)
    {
    
        do
        {
            System.out.println("Please make your selection");
            System.out.println("");
            System.out.println("(1) - New book     :     (2) - New user     :     (3) - New Load");
            Scanner scan = new Scanner(System.in);
            int menuSelect = scan.nextInt();
            switch (menuSelect)
            {
                case 1:
                    menuSelect = 1;
                    System.out.println("Selection 1");
                    System.out.println("(1) - Main Menu");
                    menuSelect=0;

                case 2:
                    menuSelect = 2;
                    System.out.println("Selection 2");

                case 3:
                    System.out.println("Selection 3");

            }while menuSelect(>0);
   
    }
}

[David Newton]

When you look at a Java tutorial or language spec, what does it say about the while syntax? It's probably something pretty close to if-statement syntax.

[Janeice DelVecchio]

You still have no way for the user to exit.... even though your syntax is off....

My suggestion?

 System.out.println("(1) - New book     :     (2) - New user     :     (3) - New Load    (0) - Exit");    

[Janus Engstrøm]

Regarding your syntax, it's a good idea to end what you've started before beginning something new:

First:

do {
	// add stuff here
} while (someBooleanExpression); // end do-while

Then add the stuff in the belly of your do-while loop...

do {
	switch (someIntegerValue) {
		case 0: {
			// do stuff @ case 0
			break;
		}
		case 1: {
			// do stuff @ case 1
			break;
		}
		default: {
			// handle values that doesn't fit the above cases
			break;
		}
	} // end switch
} while (someBooleanExpression); // end do-while

(or use an IDE that handles this bracketing for you...)


Kind regards,
Janus