Question

我正在制作一个杂货店java程序，它列出了项目的选项，并根据用户输入将它们添加到购物车。它适用于第一个选项，但之后程序无法正常运行。我似乎无法在任何地方找到这个错误！

理想情况下，我想要问的是：

您想要添加到购物车中的内容？输入数字

（让用户输入号码）

有多少？

（让用户输入号码）

您想在购物车中添加其他内容吗？（y / n）

（输入y或n）

基本上当用户输入＆＃39; 1＆＃39;它应该将它添加到购物车等，然后询问他们是否要添加另一个项目。然后打印＆＃34;您想要添加到购物车中的内容＆＃34;当我输入另一个项目编号时，它会返回到while循环的开头并打印出＆＃34;想要添加到购物车中的内容＆＃34;而不是像第一项那样实际添加项目。

破碎的输出图片

我还提供了代码：

do {        
    System.out.println("What would you like to add to your cart? Enter its corresponding number");
    choose = userin.nextInt();

    if(choose > 14) {
      System.out.println("please choose a valid option!"); 
      keepGoing = true;
    } else if(choose == 1) {
        System.out.println("how many?");    
        int quantity;
        quantity = userin.nextInt();
        cart1.addToCart(FoodItems.QUINOA, 7.00, quantity);      
    }
    System.out.print ("\nWould you like to add anything else to your cart (y/n)? ");
    keepShopping = userin.next();

    if(choose ==2) {
      System.out.println("What would you like to add to your cart? Enter its corresponding number");
      choose = userin.nextInt(); 
      System.out.println("how many?");  
      int quantity;
      quantity = userin.nextInt();
      cart1.addToCart(FoodItems.ORGEGG, 3.45, quantity);
    }
    System.out.print ("\nWould you like to add anything else to your cart (y/n)? ");
    keepShopping = userin.next();
    System.out.println("What would you like to add to your cart? Enter its corresponding number");
    choose = userin.nextInt();

    if(choose == 3) {
      System.out.println("how many?");  
      int quantity;
      quantity = userin.nextInt();
      cart1.addToCart(FoodItems.CCNTW, 2.99, quantity);
      System.out.print ("\nWould you like to add anything else to your cart (y/n)? ");
      keepShopping = userin.next();

    }
}
while (keepShopping.equals("y"));

  if(keepShopping.equals("n")) {
     System.out.println("\n");
     Register.talking();
  }
  System.out.println(cart1);
  keepGoing = false;
}

Answer 1

代码中的问题是您没有使用 else if。因此循环将不会达到while条件，直到它执行所有if情况。

这是工作代码。我还重构了你的代码以使其变得简单。

public class Cart {

    public static void main(String[] args) {

        Scanner userin = new Scanner(System.in);
        String keepShopping;
        int quantity;
        do {
            System.out.println("What would you like to add to your cart? Enter its corresponding number");
            int choose = userin.nextInt();

            if (choose > 14) {
                System.out.println("please choose a valid option!");
            }
            System.out.println("how many?");
            quantity = userin.nextInt();

            if (choose == 1) {
                cart1.addToCart(FoodItems.QUINOA, 7.00, quantity);
            }
            else if (choose == 2) {
                cart1.addToCart(FoodItems.ORGEGG, 3.00, quantity);
            }
            else if (choose == 3) {
                cart1.addToCart(FoodItems.CCNTW, 1.00, quantity);
            }
            System.out.print("\nWould you like to add anything else to your cart (y/n)? ");
            keepShopping = userin.next();
        } while (keepShopping.equals("y"));
        if (keepShopping.equals("n")) {
            System.out.println("\n");
        }
        System.out.println("");
    }

}

一会儿不能正常工作

1 个答案: