java - InputDialogs 的货币转换器 If 语句

Question

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我的项目是创建一个货币转换器，我似乎无法将 if 语句连接到用户的选择。

import javax.swing.JOptionPane;

public class Test {



    public static void main(String args[]){

    double CanadianDollar = .9813;
    double Euro = .757;
    double IndianRupee = 52.53;
    double JapaneseYen = 80.92;
    double MexicanPeso = 13.1544;
    double BritishPound = .6178;

    String input; 
    Object[] possibilities = {"Canadian Dollar", "Euro", "Indian Rupee", "Japanese Yen",
            "Mexican Peso", "British Pound"};
    String currencyChosen = (String) JOptionPane.showInputDialog( null,
         "What currency would you like to start with?:",
         "Currency Converter",
         JOptionPane.QUESTION_MESSAGE,
         null,
         possibilities,
         null);

    JOptionPane.showMessageDialog(null, "You chose to start from " + currencyChosen);

    Object[] possibilitiesToChoose = {"Canadian Dollar", "Euro", "Indian Rupee", "Japanese Yen",
            "Mexican Peso", "British Pound"};
    String convertTo = (String) JOptionPane.showInputDialog( null,
         "What currency would you like to convert to?:",
         "Currency Converter",
         JOptionPane.QUESTION_MESSAGE,
         null,
         possibilities,
         null);

    JOptionPane.showMessageDialog(null, "You chose to convert from " + currencyChosen + " to " + convertTo);


    if (currencyChosen = "Canadian Dollar")   <- This is not working

    }
}

Answer 1

尝试替换这个:

 if (currencyChosen = "Canadian Dollar") 

使用equals方法:

  if ("Canadian Dollar".equals(currencyChosen )) 
   ...

= 用于赋值，而不是检查字符串之间的相等性。