Java柠檬汁计算器

任务是：

• 在输出屏幕顶部显示任何欢迎信息

• 创建变量来保存一杯柠檬水的价格值

• 显示每杯的价格

• 询问用户的姓名，并将其存储为字符串对象。只要有可能，请按名称引用用户

• 询问用户想要订购多少杯柠檬水。将其保存为具有适当数据类型的变量

• 将圣地亚哥8%的税率作为恒定变量存储在您的计划中

• 计算小计、总税金和总价，并将其显示在屏幕上

• 询问用户想要如何支付柠檬水，并将输入保存为char变量

• 要求用户输入“m”表示货币，“c”表示信用卡，或“g”表示黄金

• 使用DecimalFormat类，使打印到屏幕上的所有货币数据显示2位小数，并显示一个“$”符号

需要帮助了解如何在我的程序中获得8%的税率作为常量变量吗 这样我就可以计算小计、总税金和总价，并将其显示在屏幕上

到目前为止，这就是我所拥有的：

import java.util.Scanner;
import javax.swing.JOptionPane;
import java.text.DecimalFormat;

public class FirstProgram {

    public static void main(String[] args) {
        double cost = 7.55;
        double amount = 7.55;
        final double CA_SALES_TAX = 0.08; 
        int tax, subtotal, total;
        subtotal = (int) (amount * cost);
        tax = (int) (subtotal * CA_SALES_TAX);
        total = tax + subtotal;

        Scanner input = new Scanner(System.in);
        double fnum = 7.55, tax1 = fnum * 0.08, answer = tax1 + fnum; 
        System.out.println("Welcome to the best Lemonade you'll ever taste! ");

        System.out.println("My lemonade would only cost you a measly: $" + amount);

        System.out.println("What is your name?");

        String first_name;
        first_name = input.nextLine();

        System.out.println("Hi " +first_name+ ", how many glasses of lemonade would you like?");
        fnum = input.nextDouble();
        System.out.println("Subtotal: $" + (amount * fnum));

        System.out.println("Tax:    $" + (tax1 * CA_SALES_TAX));
        tax1 = input.nextDouble();

---

感谢您提供的任何帮助

看起来您已经将增值税设置为常量，这就是“final”关键字的用途。至于您的代码，我看到了一些冗余，不确定您为什么要强制转换为整数。我为您想做的做了一些修改

public static void main(String[] args) {
    double cost = 7.55;
    final double CA_SALES_TAX = 0.08;
    double subtotal,tax,total;

    Scanner input = new Scanner(System.in);
    System.out.println("Welcome to the best Lemonade you'll ever taste! ");
    System.out.println("My lemonade would only cost you a measly: $" + cost);

    System.out.println("What is your name?");
    String first_name = input.nextLine();

    System.out.println("Hi " +first_name+ ", how many glasses of lemonade would you like?");
    int fnum = input.nextInt();

    //calc subtotal, tax, total 
    subtotal = fnum * cost;
    tax = subtotal *CA_SALES_TAX; 
    total = tax + subtotal;

    // print them all out 
    System.out.println("Subtotal: $" + (subtotal));
    System.out.println("Tax: $" + (tax));
    System.out.println("Total Price: $" + (total));
}

---

看起来你已经将增值税设置为常量，这就是“final”关键字的用途。至于你的代码，我看到了一些冗余，不确定你为什么要转换为整数。我为你想做的做了一些修改

public static void main(String[] args) {
    double cost = 7.55;
    final double CA_SALES_TAX = 0.08;
    double subtotal,tax,total;

    Scanner input = new Scanner(System.in);
    System.out.println("Welcome to the best Lemonade you'll ever taste! ");
    System.out.println("My lemonade would only cost you a measly: $" + cost);

    System.out.println("What is your name?");
    String first_name = input.nextLine();

    System.out.println("Hi " +first_name+ ", how many glasses of lemonade would you like?");
    int fnum = input.nextInt();

    //calc subtotal, tax, total 
    subtotal = fnum * cost;
    tax = subtotal *CA_SALES_TAX; 
    total = tax + subtotal;

    // print them all out 
    System.out.println("Subtotal: $" + (subtotal));
    System.out.println("Tax: $" + (tax));
    System.out.println("Total Price: $" + (total));
}

---

public static final double CA\u SALES\u TAX=0.08；

-但是您需要在类级别（不在您的方法中）声明它

public static final double CA\u SALES\u TAX=0.08；

-但是您需要在类级别（不在您的方法中）声明它