在程序开发中往往遇到进制的转换问题。十进制转BCD的几种算法，仅供初学者参考。-Hex conversion problems often encountered in the program development. The decimal transferred several algorithms of the BCD, the only reference for beginners.

Wirksheet for calculating bin dec hex oct bcd code

2.1 C++的輸出物件cout 2.2 cout物件的格式化函式 2.2.1 欄位寬設定－ cout.width(n) setw( ) 2.2.2 精確度設定－cout.precision( ) setprecision( ) 2.2.3 進位制設定－dec, hex, oct 2.2.4 指定多餘格數字元－cout.fill( ) setfill( ) 2.2.5 小數位數設定－cout.setf( ) 2.3 C++的輸入物件cin -2.1 C++