I’m writing a simple vending machine program and I’m unsure how to do a few things. So far my program prints a menu with 5 items and repeats until the customer hits ‘x’ or exits. I would like for the loop to also terminate when the customer is out of money, but I’m unsure how to do that. I also tried to make a print statement that says an item is out of stock when the quantity is 0, but I couldn’t get that to work. Any help is appreciated!

import java.util.Scanner;  public class Testing {  static void MilkA() {     System.out.println("\nYou have purchased Milk for $  2.00");     return; }  static void SodaB() {     System.out.println("\nYou have purchased Soda for $  2.25");     return; }  static void CandyBarC() {     System.out.println("\nYou have purchased a Candy bar for $  1.25");     return; }  static void GummyBearsD() {     System.out.println("\nYou have purchased Gummy Bears for $  1.50");     return; }  static void ChipsE() {     System.out.println("\nYou have purchased chips for $  1.00");     return; } static void ExitX() {     System.exit(0); }   public static void main(String[] args) {  Scanner scnr = new Scanner(System.in); System.out.println("Please enter how much money you have to spend (enter -1 to shut down"); double startingAmount = scnr.nextDouble();  double milkPrice = 2.00; double sodaPrice = 2.25; double candyBarPrice = 1.25; double gummyBearsPrice = 1.50; double chipsPrice = 1.00;   int milkQuantity = 5;  int sodaQuantity = 4;  int candyBarQuantity = 5;  int gummyBearsQuantity = 6;  int chipsQuantity = 6;  char quit = 'x'; String choice;  Scanner scan = new Scanner(System.in);  while (quit != 'y') {     System.out.println("Welcome to the Vending Machine!"              + "\nI sense that you are hungry... This is what I have to offer:"             + "\nPlease make a selection"             + "\nItem               Price           Quantity"             + "\nMilk - A           $  2.00               " + milkQuantity             + "\nSoda - B           $  2.25               " + sodaQuantity             + "\nCandy Bar - C      $  1.2                " + candyBarQuantity             + "\nGummy Bears - D    $  1.50               " + gummyBearsQuantity             + "\nChips - E          $  1.00               " + chipsQuantity             + "\nExit = X");     choice = scan.nextLine().toUpperCase();      switch (choice) {     case "A":         MilkA();         double amountAfterMilk = startingAmount - milkPrice;         double changeMilk = amountAfterMilk -= milkPrice;         System.out.println("You now have $  " + changeMilk);         milkQuantity -= 1;         break;      case "B":         SodaB();         double amountAfterSoda = startingAmount - sodaPrice;         double changeSoda = amountAfterSoda -= sodaPrice;         System.out.println("You now have $  " + changeSoda);         sodaQuantity -= 1;         break;      case "C":         CandyBarC();         double amountAfterCandyBar = startingAmount - candyBarPrice;         double changeCandyBar = amountAfterCandyBar -= candyBarPrice;         System.out.println("You now have $  " + changeCandyBar);         candyBarQuantity -= 1;         break;      case "D":         GummyBearsD();         double amountAfterGummyBears = startingAmount - gummyBearsPrice;         double changeGummyBears = amountAfterGummyBears -= gummyBearsPrice;         System.out.println("You now have $  " + changeGummyBears);         gummyBearsQuantity -= 1;         break;      case "E":         ChipsE();         double amountAfterChips = startingAmount - chipsPrice;         double changeChips = amountAfterChips -= chipsPrice;         System.out.println("You now have $  " + changeChips);         chipsQuantity -= 1;         break;      case "X":         ExitX();         default:             System.out.println("That's not an option.");              if (milkQuantity == 0) {                 System.out.println("Out of Stock");                 }          }      }  } 

}