Question

我的循环语句出现问题，如果没有恢复原来的循环条件，就无法正常执行。另外，如果我希望我的最终输出包含所购买产品总数的定价值，我将如何实现这一目标？

所需的最终产品：客户购买所有9件商品

请输入您的姓名：John Smith

GRAPEFRUIT PRODUCT


gPod shuffle $ 49

gPod Touch $ 299

gPad Mini $ 329

gPad 2 $ 399

gPhone $ 199

gMac $ 1299

MacNovel Pro $ 1199

MacNovel Air $ 999

MiniMac $ 599

完成我的订单

请从上面的菜单中选择一个项目：5

请从上面的菜单中选择其他项目：2

请从上面的菜单中选择其他项目：7

请从上面的菜单中选择其他项目：9

请从上面的菜单中选择其他项目：3

请从上面的菜单中选择其他项目：4

请从上面的菜单中选择其他项目：6

请从上面的菜单中选择其他项目：1

请从上面的菜单中选择其他项目：8

请从上面的菜单中选择其他项目：10谢谢   与Grapefruit公司订购，John Smith

订购的商品总数：9

订购商品的价格：$ 5371

销售税：$ 349.115

应付总额：$ 5720.115

这是我的代码：

public static void main(String[] args) {

        // Declare Variables
        Scanner input = new Scanner (System.in);
        String CustomerName;
        int gpodShuffle = 1;
        int gpodTouch = 2;
        int gpadMini = 3; 
        int gpadTwo = 4;
        int gphone = 5;
        int gmac = 6;
        int macnovelPro = 7;
        int macnovelAir = 8;
        int miniMac = 9;
        int nNumber = 0;
        int nProducts = 0;
        int nTotal = 0;

        //Declare Constants 
        final int SENTINEL = 10;
        final double SALES_TAX = 6.5;
        final int GPOD_SHUFFLE = 49;
        final int GPOD_TOUCH = 299;
        final int GPAD_MINI = 329;
        final int GPAD_TWO = 399;
        final int GPHONE = 199;
        final int GMAC = 1299;
        final int MAC_NOVELPRO = 1199;
        final int MAC_NOVELAIR = 999;
        final int MINI_MAC = 599;

        //Prompt user to enter name
        System.out.println("Please enter your name: ");

        //Enter user name
        CustomerName = input.nextLine();

        //Print Blank Line 
        System.out.println("");

        //Begin Product Listing
        System.out.println("GRAPEFRUIT PRODUCT:");

        System.out.println("1. gPod shuffle $49");

        System.out.println("2. gPod Touch   $299");

        System.out.println("3. gPad Mini    $329");

        System.out.println("4. gPad 2       $399");

        System.out.println("5. gPhone       $199");

        System.out.println("6. gMac         $1299");

        System.out.println("7. MacNovel Pro $1199");

        System.out.println("8. MacNovel Air $999");

        System.out.println("9. MiniMac      $599");

        System.out.println("10. Complete my order");

        //Keep reading until the input is 10
        while (nNumber != SENTINEL) {
            //Calculate entered items
            nTotal = nTotal + nNumber;

            nProducts++;

        System.out.println("\nPlease select an item from the menu above: ");

        //Read number entered by the user
        nNumber = input.nextInt();

        if (nNumber == SENTINEL) 
        System.out.println("Thank you for ordering with Grapefruit Company, " + CustomerName);
        else if  (nNumber != SENTINEL) 
        System.out.println("Please select another item from the menu above: ");
        } //End Loop



        //Process selections entered by the user

            //Increment count 


            //Print blank line to screen
            System.out.println("");

            //Total amount of product ordered
            System.out.println("Total items ordered: ");

            //Total price of items ordered
            System.out.println("Price of items ordered: ");

            //Sales tax associated with the purchase
            System.out.println("Sales tax: " + SALES_TAX);

            //Total amount due by the customer to Grapefruit Co. 
            System.out.println("Total amount due: ");


      }

    }

Answer 1

对于某些要添加的类来说，这是非常令人烦恼的，因此您可以轻松地遍历这些项目。

然而，你可以在这个场景中做些什么：

保持数组中项目的价格。

int [] itemPrices = {49,299,329,399,199,1299,1199,999,599};

更新您的打印报表

System.out.println("1. gPod shuffle $" + prices[0]);

System.out.println("2. gPod Touch   $" + prices[1]);

System.out.println("3. gPad Mini    $" + prices[2]);

System.out.println("4. gPad 2       $" + prices[3]);

System.out.println("5. gPhone       $" + prices[4]);

System.out.println("6. gMac         $" + prices[5]);

System.out.println("7. MacNovel Pro $" + prices[6]);

System.out.println("8. MacNovel Air $" + prices[7]);

System.out.println("9. MiniMac      $" + prices[8]);

更新while循环以引用这些商品价格

// Keep reading until the input is 10
while (nNumber != SENTINEL) 
{

    System.out.println("\nPlease select an item from the menu above: ");

    // Read number entered by the user
    nNumber = input.nextInt();

    if (nNumber == SENTINEL) 
    {   
        System.out.println("Thank you for ordering with Grapefruit Company, " + CustomerName);
        // The user's just entered the value held for SENTINEL - leave the while loop.
        break;
    } 

    // Calculate the total price.
    nTotal = nTotal + prices[nNumber-1];


    // Increment the total number of products entered.
    nProducts++;
}

更新最终的打印声明：

    //Total amount of product ordered
    System.out.println("Total items ordered: " + nProducts);

    //Total price of items ordered
    System.out.println("Price of items ordered: "+nTotal);

    //Sales tax associated with the purchase
    System.out.println("Sales tax: " + SALES_TAX);

我会告诉你如何得到应付的总金额：）

Answer 2

要解决您遇到的此连接问题：

System.out.println("Total amount due: " + ((SALES_TAX * nTotal) + nTotal));

这意味着在将其转换为字符串之前执行完整计算。

但是这背后的数学是错误的，而是执行以下操作：

// Calculate the amount of tax.
double salesTax = (SALES_TAX/100) * nTotal;
System.out.println("Sales tax: " + salesTax);

然后你应该这样做：

//Total amount due by the customer to Grapefruit Co. 
System.out.println("Total amount due: " + (salesTax + nTotal));

While-Loop完成问题和最终值计算

2 个答案: