Return updated value in another method

I have two methods where I update the value of a variable in one method, and I want to call the updated value in the second method.

// Instance variables
private int numOfFirstClassSeats = 48;
...

In my bookFirstClassSeats method, I subtract the number of passengers from the number of seats available.

numOfFirstClassSeats -= numOfFirstClassAdults;

I also have the following getter and setter methods for it.

public int getNumOfFirstClassSeats() {
    return numOfFirstClassSeats;
}

public void setNumOfFirstClassSeats(int numOfFirstClassSeats) {
    this.numOfFirstClassSeats = numOfFirstClassSeats;
}

So in the first method, I have called the get and set method.

public void bookFirstClassSeats() {
    ...

    // Subtract the number of passengers from the number of seats available.
    numOfFirstClassSeats -= numOfFirstClassAdults;
    System.out.println("Available Seats: " + getNumOfFirstClassSeats());
}

The System.out.println() prints the correct, updated value, 46.

In my second method, I'd like to display the number of available seats as shown below.

public void printAvailableSeats() {
    System.out.println("First Class: " + getNumOfFirstClassSeats();
}

Problem: When I run this feature I get the same original value, 48. I understand why I'm not getting the updated value, but I haven't figured out yet how to call it.

EDIT: To clarify, both of these methods are in the same class. I have another class called BookingSystem.java, and I use it to run the main method and call the methods above from another class.

Here is my main method code:

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String input;

    do {
		System.out.println("\n~ BOOKING SYSTEM ~");
		System.out.println("------------------");
		System.out.println("A. Book Seats");
		System.out.println("B. View Available Seats");
        System.out.println("X. Exit\n");

		System.out.print("Select an option: ");
		input = sc.nextLine();

        if (input.length() > 1)
			System.out.println("ERROR: You can only enter a single character!");
		else {
			input = input.toUpperCase();
			
			switch(input) {
				case "A":
					new BookingReceipt().bookSeats();
					break;
				
				case "B":
					new BookingReceipt().printAvailableSeats();
					break;
				
				case "X":
					System.out.println("INFO: You have exited the booking system.");
					break;
				
				default:
					System.out.println("ERROR: Invalid input!");
			}
		}
	} while (input.equals("X") == false);
	
	sc.close();
}

well, you made that setter; call it!

For example:

public void bookFirstClassSeats() {
    ...

    // Subtract the number of passengers from the number of seats available.
    numOfFirstClassSeats -= numOfFirstClassAdults;
    setNumOfFirstClassSeats(numOfFirstClassSeats);
    System.out.println("Available Seats: " + getNumOfFirstClassSeats());
}

Note the object oriented mindset goes a little further than rote getters and setters. Whatever class has the numOfFIrstClassSeats field should probably have the book method, too.

I suspect you are creating a fresh object of the class containing field private int numOfFirstClassSeats = 48;. Hence, you're getting the default value. You should use the same object rather creating a new one or you can make that class singleton if this the problem. It would be clear if you can share your main calling method's definition.

As I suspected, you are creating fresh object just create BookingReceipt object once.

Create BookingReceipt before do loop starts.

public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String input;
BookingReceipt receipt = new BookingReceipt();
do {
    System.out.println("\n~ BOOKING SYSTEM ~");
    System.out.println("------------------");
    System.out.println("A. Book Seats");
    System.out.println("B. View Available Seats");
    System.out.println("X. Exit\n");

    System.out.print("Select an option: ");
    input = sc.nextLine();

    if (input.length() > 1)
        System.out.println("ERROR: You can only enter a single character!");
    else {
        input = input.toUpperCase();

        switch(input) {
            case "A":
                receipt.bookSeats();
                break;

            case "B":
                receipt.printAvailableSeats();
                break;

            case "X":
                System.out.println("INFO: You have exited the booking system.");
                break;

            default:
                System.out.println("ERROR: Invalid input!");
        }
    }
} while (input.equals("X") == false);

sc.close();
}