c语言的头文件#include <limits.h>
CHAR_BIT Number of bits in the smallest variable that is not a bit field. 8
SCHAR_MIN Minimum value for a variable of type signed char. –128
SCHAR_MAX Maximum value for a variable of type signed char. 127
UCHAR_MAX Maximum value for a variable of type unsigned char. 255 (0xff)
CHAR_MIN Minimum value for a variable of type char. –128; 0 if /J option used
CHAR_MAX Maximum value for a variable of type char. 127; 255 if /J option used
MB_LEN_MAX Maximum number of bytes in a multicharacter constant. 2
SHRT_MIN Minimum value for a variable of type short. –32768
SHRT_MAX Maximum value for a variable of type short. 32767
USHRT_MAX Maximum value for a variable of type unsigned short. 65535 (0xffff)
INT_MIN Minimum value for a variable of type int. –2147483647 – 1
INT_MAX Maximum value for a variable of type int. 2147483647    www.2cto.com
UINT_MAX Maximum value for a variable of type unsigned int. 4294967295 (0xffffffff)
LONG_MIN Minimum value for a variable of type long. –2147483647 – 1
LONG_MAX Maximum value for a variable of type long. 2147483647
ULONG_MAX Maximum value for a variable of type unsigned long. 4294967295 (0xffffffff)
最常用的是整数的最大值INT_MAX与最小值INT_MIN，代表无穷大与无穷小