Question

编写允许用户输入多个值的程序，然后程序应将以磅（GBP）输入的值转换为多种不同的货币。菜单应如下所示：

输入值并输入-1以停止
欧元
元
颜
卢比
退出

当选择2,3,4或5时，程序应显示以原始磅数和转换后的货币输入的每个值，以及所有数字和转换总数的总和。

public class Money {
    public static void main(String[] args) {
        System.out.println("Enter values and type -1 to stop"); 
        System.out.println("'1' = Euros"); 
        System.out.println("'2' = Dollars"); 
        System.out.println("'3' = Yen"); 
        System.out.println("'4' = Rupees"); 
        System.out.println("'5' = Exit"); 

        int count=0;
        String exit = "-1", euro="E";

        Scanner scan = new Scanner(System.in);

        System.out.println();
        System.out.print("Convert to: ");

        while (!scan.hasNext("[E, D, Y, R, X]+")) {
            System.out.print("Invalid value, enter Surname again: ");
            scan.next();
        }

        String exTo = scan.next();

        ArrayList<String> num = new ArrayList<String>();

        while (true) {
            count++;
            System.out.print("|| Enter values "+count+" in (P)Pounds : ");

            while (!scan.hasNextDouble()) {
                System.out.print("Invalid value, try again: ");
                scan.next();
            }
            num.add(scan.next());

            if(num.contains(exit)){
                String ar[]=num.toArray(new String[num.size()]);
                ar=num.toArray(ar);

                System.out.println("Result: "+ num);

                scan.close();
                break;
            }
        }
    }
}

Answer 1

试试这个：

import java.util.*;
class Money {
    public static void main(String[] args) {
        System.out.println("Enter values and type -1 to stop"); 
        System.out.println("'1' = Euros"); 
        System.out.println("'2' = Dollars"); 
        System.out.println("'3' = Yen"); 
        System.out.println("'4' = Rupees"); 
        System.out.println("'5' = Exit"); 
    int count=0;
    String exit = "-1", euro="E";

    Scanner scan = new Scanner(System.in);

    System.out.println();
    System.out.print("Convert to: ");

    while (!scan.hasNext("[E, D, Y, R, X]+")) {
        System.out.print("Invalid value, enter Surname again: ");
        scan.next();
    }

    String exTo = scan.next();

    ArrayList<String> num = new ArrayList<String>();

    while (true) {
        count++;
        System.out.print("|| Enter values "+count+" in (P)Pounds : ");

        while (!scan.hasNextDouble()) {
            System.out.print("Invalid value, try again: ");
            scan.next();
        }
        num.add(scan.next());

        if(num.contains(exit)){
            for(int i=0;i<num.size();i++){
            num.set(i,Integer.toString((Integer.parseInt(num.get(i))*2)));
            }
            System.out.println("Result: "+ num);

            scan.close();
            break;
        }
    }
}
}

删除最后一个输入（-1）

在打印num.remove("-1");

之前添加此行

Answer 2

如何将数组列表中的每个数字与用户类型相乘数组列表数组中的数字如下所示：[20,30,40]和在我需要之后，结果显示像每个数字相乘例如2 [40,60,80]

如何循环遍历列表，并进行计算？

for (Integer i : yourList)
  i *= 2;

或者如果你想进行更复杂的计算，你可以尝试使用番石榴Lists.transform(list, func)。

http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/collect/Lists.html#transform(java.util.List，com.google.common.base.Function）

将arraylist中的每个数字相乘

2 个答案: