Question

我正在写这个程序，让你输入每个季度，硬币，镍币和便士的金额，并以$ $返回金额。在那之后，我希望能够将他们生产的美元金额相加，而无需再次输入所有硬币金额。有任何想法吗？提前谢谢。

import java.util.*;

public class HalfDollar {
  public static final Scanner CONSOLE = new Scanner(System.in);

  public static void main(String[] args) {
    quarterDollarAmount( );
    dimeDollarAmount( );
    nickelDollarAmount( );
    pennyDollarAmount( );
    totalDollarAmount( );
  }

  public static double quarterDollarAmount( ) {
    System.out.print("Enter the number of quarters: ");
    int quarterDollar = CONSOLE.nextInt( );
    double amount = quarterDollar * 0.25;
    System.out.println(quarterDollar + " Quarter are $" + amount);
    return amount;
  }

  public static double dimeDollarAmount( ) {
    System.out.print("Enter the number of dimes: ");
    int dimeDollar = CONSOLE.nextInt( );
    double amount = dimeDollar * 0.10;
    System.out.println(dimeDollar + " Dimes are $" + amount);
    return amount;
  }

  public static double nickelDollarAmount( ) {
    System.out.print("Enter the number of nickels: ");
    int nickelDollar = CONSOLE.nextInt( );
    double amount = nickelDollar * 0.05;
    System.out.println(nickelDollar + " Nickels are $" + amount);
    return amount;
  }

  public static double pennyDollarAmount( ) {
    System.out.print("Enter the number of pennies: ");
    int pennyDollar = CONSOLE.nextInt( );
    double amount = pennyDollar * 0.01;
    System.out.println(pennyDollar + " Pennies are $" + amount);
    return amount;
  }

  public static double totalDollarAmount( ) {
    double quarter = quarterDollarAmount();
    double dime = dimeDollarAmount();
    double nickel = nickelDollarAmount();
    double penny = pennyDollarAmount();
    double total = quarter + dime + nickel + penny;
    System.out.println("Total amount is $" + total);
    return total;
  }
}

Answer 1

您没有对变量做任何事情。只是打电话给他们，然后他们就会超出范围。

您可以将返回的值存储在全局变量中以便以后使用。

private double quarter, dime, total;

public static void main(String[] args) {
     quarter = quarterDollarAmount();
     dime = dimeDollarAmount();
     total = (quarter + dime);
     s.o.p(total);

}

如果您在打印后不关心该值，您可以使用局部变量对其进行总计，或者按照以下方法总计您的方法。

public static void main(String[] args) {
     s.o.p(quarterDollarAmount( ) + dimeDollarAmount( ) + ....);
}

要使您的值达到2位小数，请使用以下内容：

DecimalFormat format = new DecimalFormat("#.00");
Double total_formatted = Double.parseDouble(format.format(total));
s.o.p(total_formatted);

强制该值具有2个小数位，并且小数位左边有一个可选的位数。

最后，你可能不想让一切都变得静止。它基本上打败了面向对象的点，因为静态变量将持续存在于类的所有对象中。

Answer 2

嗯，这对我来说就像是一个家庭作业问题。如果您真的是编写此代码的人，那么任何数量的解决方案都应该非常明显。但无论如何，我不会判断你的旅程。由于您从每个方法返回金额，因此只需保持所有金额的运行总计，然后更改totalDollarAmount方法以将总计作为输入而不是再次要求它：

double total = 0.0;
total += quarterDollarAmount( );
total += dimeDollarAmount( );
total += nickelDollarAmount( );
total += pennyDollarAmount( );
totalDollarAmount( total );

为什么我必须输入两次数据？

2 个答案: