Question

我写的这个程序有点问题。当我使用CMD运行它时，它会给我一些错误，例如变量＆＃34; totalFry＆＃34;即使它是全局变量也无法定义。任何帮助都会很棒，非常感谢！（注意：这是我第一次编写循环/代码时）

这个想法是给用户3个选择，让用户输入一个选项（1-3）并且表示选项似乎提示用户输入他们想要的团队数量。
接下来，程序将询问用户如果他们想要结束订单，假设他们输入＆＃34;是＆＃34;该程序如果用户输入，将询问用户是否想要结束该程序＆＃34;是＆＃34;程序将进行并总计成本并显示它。
程序结束

代码：

import java.io.*;
import java.util.Scanner; 

//Lab 4_5
public class Lab4_5 {
    static Scanner keyboard = new Scanner(System.in);

    // Declare local variables
    static double totalBurger, totalFry, totalSoda;
    static int option, burgerCount, fryCount, sodaCount;

    // The main method
    public static void main(String[] args) {

        //Add a loop to run program again
        String endProgram = "no";
        while (endProgram.equals("no"))

            //Add a loop to take in order
            String endOrder = "no";
        while (endOrder.equals("no"))

            // Add statements to display the menu, get the user choice, and assign it to option
            System.out.println("Enter 1 for Yum Yum Burger");
        System.out.println("Enter 2 for Grease Yum Fires");
        System.out.println("Enter 3 for Soda Yum");

        //Add a Select Case statement based on the value of option
        int option = 0;
        option = keyboardnextInt();

        //When option = 1
        if (option == 1)
            double totalBurger = 0;
        int burgerCount = 0;
        System.out.println("Enter the number of burgers you want ");
        burgerCount = keyboard.nextDouble();
        totalBurger = totalBurger + burgerCount * .99;
        //When option = 2
        if (option == 2)
            double totalFry = 0;
        int fryCount = 0;
        System.out.println("Enter the number of fires you want ");
        fryCount = keyboard.nextDouble();
        totalFry = totalFry + fryCount * .79;
        //When option = 3
        if (option == 3)
            double totalSoda = 0;
        int sodaCount = 0;
        System.out.println("Enter the number of sodas you want ");
        sodaCount = keyboardnext.Double();
        totalSoda = totalSoda + sodaCount * 1.09;

        //Imput if user wants to end order
        System.out.println("Do you want to end your order? (Enter no to add more items ) ");
        endOrder = keyboard.next();

        //Call
        clacTotal();
        printReceipt();

        //Ask user if they want to end the program
        System.out.println("Do you want to end the program? (Enter no to process a new order) ");
        endProgram = keyboard.next();
    }

    //Calculate the total amount
    public static void calcTotal() {
        double total = 0;
        double tax = 0;
        double subtotal = 0;
        //Add statements to calc total with tax and call printReceipt
        calcTotal = totalBurger + totalFry + totalSoda * .06;
    }

    public static void printReceipt() {
        //Add statements to display the total as shown above
        System.out.println("Your total is $" + calcTotal);
    }
}

Answer 1

您的代码存在许多问题，包括：

在if's和loops
创建重复变量。
在ints上使用keyboard.nextDouble（）

加上一些拼写错误。

以下代码至少应该按照您的需要编译和工作。

import java.util.Scanner;

public class Lab4_5 {
static Scanner keyboard = new Scanner(System.in);

// Declare local variables
static double totalBurger, totalFry, totalSoda, calcTotal;
static int option, burgerCount, fryCount, sodaCount;

// The main method
public static void main(String[] args) {

    //Add a loop to run program again
    String endProgram = "no";
    while (endProgram.equals("no")){

        //Add a loop to take in order
        String endOrder = "no";
        while (endOrder.equals("no")){

        // Add statements to display the menu, get the user choice, and assign it to option
            System.out.println("Enter 1 for Yum Yum Burger");
            System.out.println("Enter 2 for Grease Yum Fires");
            System.out.println("Enter 3 for Soda Yum");

            //Add a Select Case statement based on the value of option
            int option = 0;
            option = keyboard.nextInt();

            //When option = 1
            if (option == 1){
                totalBurger = 0;
                burgerCount = 0;
                System.out.println("Enter the number of burgers you want ");
                burgerCount = keyboard.nextInt();
                totalBurger = totalBurger + burgerCount * .99;
            }   
            //When option = 2
            if (option == 2){
                System.out.println("Enter the number of fires you want ");
                fryCount = keyboard.nextInt();
                totalFry = totalFry + fryCount * .79;
            }   
            //When option = 3
            if (option == 3){
                System.out.println("Enter the number of sodas you want ");
                sodaCount = keyboard.nextInt();
                totalSoda = totalSoda + sodaCount * 1.09;
            }   

            //Imput if user wants to end order
            System.out.println("Do you want to end your order? (Enter no to add more items ) ");
            endOrder = keyboard.next();
       }

        calcTotal();
        printReceipt();

      //Ask user if they want to end the program
        System.out.println("Do you want to end the program? (Enter no to process a new order) ");
        endProgram = keyboard.next();
    }
}

  //Calculate the total amount
  public static void calcTotal() {

      //Add statements to calc total with tax and call printReceipt
      calcTotal = totalBurger + totalFry + totalSoda * .06;
  }

 public static void printReceipt() {
    //Add statements to display the total as shown above
    System.out.println("Your total is $" + calcTotal);
  }
}

java循环程序无法检测符号

1 个答案: