Question

我有以下代码（我不是很懂电脑，所以要温和），用户应该能够输入单独的硬币金额，程序会告诉用户他们在所述硬币数量上有多少钱。

import java.util.*;

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

  public static void main(String[] args) {

    System.out.println ("Lab 2 by Maria T Williams\n");

    quarterAmount( );
    dimeAmount( );
    nickelAmount( );
    pennyAmount( );
  }

  public static void quarterAmount( ) {
    System.out.print("Enter the number of quarters: ");
    int quarterNumber = CONSOLE.nextInt( );
    double amount = quarterNumber * 0.25;
    System.out.print(quarterNumber + " You have $" + amount);
    System.out.println(" worth of quarters.");
  }

  public static void dimeAmount( ) {
    System.out.print("Enter the number of dimes: ");
    int dimeNumber = CONSOLE.nextInt( );
    double amount = dimeNumber * .10;
    System.out.print(dimeNumber + " You have $" + amount);
    System.out.println(" worth of dimes.");
  }

  public static void nickelAmount( ) {
    System.out.print("Enter the number of nickels: ");
    int nickelNumber = CONSOLE.nextInt( );
    double amount = nickelNumber * 0.05;
    System.out.print(nickelNumber + " You have $" + amount);
    System.out.println(" worth of nickels.");
  }

  public static void pennyAmount( ) {
    System.out.print("Enter the number of pennies: ");
    int pennyNumber = CONSOLE.nextInt( );
    double amount = pennyNumber * 0.01;
    System.out.print(pennyNumber + " You have $" + amount);
    System.out.println(" worth of pennies.");
  }
}

如果我输入的数量在100s不是“0”的地方我很好。但是，如果我进入，比如两个季度，我会收回“0.5美元”而不是“0.50美元”。

Answer 1

您可以使用DecimalFormat强制将数字格式化为您喜欢的格式。 E.g：

DecimalFormat df = new DecimalFormat("#.00");
double amount = dimeNumber * .10;
System.out.print(dimeNumber + " You have $" + df.format(amount) + " worth of dimes.");

Answer 2

输出计算结果时，您可以使用DecimalFormat，如下所示：

    DecimalFormat f = new DecimalFormat("#0.00");
    System.out.println(f.format(dimeNumber));

用小数点数计数变化（可能是简单的解决方案）

2 个答案: