30行，金額轉人民幣大寫的代碼

金額轉人民幣大寫是一種常見的要求，但是這一看似簡單的要求，實現起來卻並不容易。

前不久，我被問到了這樣一道題，當時寫了個演算法，昨天晚上又和BJDP的人們討論了一下，覺得很有必要把這個演算法寫下來。

總共37行，去掉空行還不到30行，就不多囉嗦解釋了。

 

 1 public class ChineseCurrencyConverter { 2  3     private static final String[] UNITS = {"億","仟","佰","拾","萬","仟","佰","拾","" }; 4     private static final String[] CHINESE_NUMBER = {"零","壹","貳","三","肆","伍","陸","柒","捌","玖"}; 5  6     public static String convert(long yuan) { 7  8         if (yuan >= 1e9 || yuan < 0) { 9             return "這個數字超出解析範圍了";10         }11         String amount = String.valueOf(yuan);12         int len = amount.length();13         int unitsLen = UNITS.length;14 15         String chineseCurrency = "";16         for (int i = len - 1; i >= 0; i--) {17             chineseCurrency = number(amount.charAt(i)) + unit(amount.charAt(i), unitsLen - len + i) +chineseCurrency;18         }19 20         chineseCurrency = chineseCurrency.replaceAll("零+","零");21         chineseCurrency =  chineseCurrency + "元整";22         chineseCurrency = chineseCurrency.replaceAll("零萬","萬");23         chineseCurrency = chineseCurrency.replaceAll("零元","元");24         return chineseCurrency;25     }26 27     private static String number(char number) {28         return CHINESE_NUMBER[Integer.parseInt(String.valueOf(number))];29     }30 31     private static String unit(char number, int pos) {32         if(number == '0' && pos != UNITS.length - 5) {33             return "";34         }35         return UNITS[pos];36     }37 }

 

 

下面是一些用來測試的代碼：

 1 public class TestConverter  { 2  3     public static void main(String[] args) { 4         System.out.println(ChineseCurrencyConverter.convert(100)); 5         System.out.println(ChineseCurrencyConverter.convert(130)); 6         System.out.println(ChineseCurrencyConverter.convert(102)); 7         System.out.println(ChineseCurrencyConverter.convert(124)); 8         System.out.println(ChineseCurrencyConverter.convert(1000)); 9         System.out.println(ChineseCurrencyConverter.convert(10000));10         System.out.println(ChineseCurrencyConverter.convert(100000));11         System.out.println(ChineseCurrencyConverter.convert(1000000));12         System.out.println(ChineseCurrencyConverter.convert(10000000));13         System.out.println(ChineseCurrencyConverter.convert(10000000));14         System.out.println(ChineseCurrencyConverter.convert(100000000));15         System.out.println(ChineseCurrencyConverter.convert(1000000000));16         System.out.println(ChineseCurrencyConverter.convert(1002));17         System.out.println(ChineseCurrencyConverter.convert(1020));18         System.out.println(ChineseCurrencyConverter.convert(1200));19         System.out.println(ChineseCurrencyConverter.convert(10003));20         System.out.println(ChineseCurrencyConverter.convert(10030));21         System.out.println(ChineseCurrencyConverter.convert(10033));22         System.out.println(ChineseCurrencyConverter.convert(10330));23         System.out.println(ChineseCurrencyConverter.convert(13030));24         System.out.println(ChineseCurrencyConverter.convert(100030));25         System.out.println(ChineseCurrencyConverter.convert(100003));26         System.out.println(ChineseCurrencyConverter.convert(100300));27         System.out.println(ChineseCurrencyConverter.convert(103000));28         System.out.println(ChineseCurrencyConverter.convert(100303));29         System.out.println(ChineseCurrencyConverter.convert(1000004));30         System.out.println(ChineseCurrencyConverter.convert(10000005));31         System.out.println(ChineseCurrencyConverter.convert(10000006));32         System.out.println(ChineseCurrencyConverter.convert(12000006));33         System.out.println(ChineseCurrencyConverter.convert(10030006));34         System.out.println(ChineseCurrencyConverter.convert(10200006));35         System.out.println(ChineseCurrencyConverter.convert(100000007));36         System.out.println(ChineseCurrencyConverter.convert(1000000008));37 38     }39 }

 

這些數字測試的結果還都正確。

這裡沒有處理角和分，留給有想法的同學去嘗試一下吧。