Q:各种基本数据类型的范围和精度如何？                                                                                   
A:Type Name       Bytes   Other Names        Range of Values                                                           
  int             *       signed (int)       System dependent                                                          
  char            1       signed char        -128 to 127                                                               
  long            4       (signed) long int  -2,147,483,648 to 2,147,483,647
  float           4       none               3.4E +/- 38 (7 digits)
  double          8       none               1.7E +/- 308 (15 digits)
  long double     10      none               1.2E +/- 4932 (19 digits)
  //资料来源：MSDN Oct2001，但是实际测试有些并不符合