货币转换程序

Question

我正在尝试制作一个程序，您可以输入英镑的金额并转换为美元，反之亦然。为什么我的代码错了？你能否解决它并告诉我为什么你做了你所做的事情。

package currencyConverter; 

import java.io.Console; 
import java.util.Scanner; 
public class ECurrencyConverter { 

    public static void main(String[] args){ 
     currency(); 
    } 

    public static void currency(){ 
     int choice; 

     Scanner keyboard = new Scanner(System.in); 

     System.out.println("What would you like to convert?"); 
     System.out.println("1. GBP to USD?"); 
     System.out.println("2. USD to GBP?"); 

     choice = keyboard.nextInt(); 

     if(choice == 1){ 
     float XUSD = (float) 1.64; 
      Console console = System.console(); 
      String input1 = console.readLine("Enter GBP to be converted to USD:"); 
      float amount1 = input1 * XUSD; 
     }else if (choice == 2){ 
     float XGBP = (float) 0.64; 
      Console console = System.console(); 
      String input2 = console.readline("Enter USD to be converted to GBP:"); 
      float amount2 = input2 * XGBP; 
     }else if (choice > 2 || choice < 1){ 
      System.out.println("Please pick either option 1 or 2."); 
     } 
    }  

} 

Answer 1

没有必要切换到控制台 - 您可以继续使用您的扫描仪。这里是可用的版本：

public static void main(String[] args) { 
    currency(); 
} 

public static void currency(){ 
    int choice; 

    Scanner keyboard = new Scanner(System.in); 

    System.out.println("What would you like to convert?"); 
    System.out.println("1. GBP to USD?"); 
    System.out.println("2. USD to GBP?"); 

    choice = keyboard.nextInt(); 

    if(choice == 1){ 
     float XUSD = (float) 1.64; 
     System.out.println("Enter GBP to be converted to USD:"); 
     System.out.println("USD: " + keyboard.nextFloat() * XUSD); 
    } else if (choice == 2){ 
     float XGBP = (float) 0.64; 
     System.out.println("Enter USD to be converted to GBP:"); 
     System.out.println("GBP: " + keyboard.nextFloat() * XGBP); 
    } else if (choice > 2 || choice < 1){ 
     System.out.println("Please pick either option 1 or 2."); 
    } 
} 

而且，你的代码甚至不应该编译，因为你正试图通过一个float乘以一个String。您可以拨打Float.parseFloat(..)将String转换为float。