The header <limits.h> defines constants for the sizes of integral types. The values below are acceptable minimum magnitudes; larger values may be used. CHAR_BIT
8
bits in a char
CHAR_MAX
UCHAR_MAX or SCHAR_MAX
maximum value of char
CHAR_MIN
0 or SCHAR_MIN
maximum value of char
INT_MAX
32767
maximum value of int
INT_MIN
-32767
minimum value of int
LONG_MAX
2147483647
maximum value of long
LONG_MIN
-2147483647
minimum value of long
SCHAR_MAX
+127
maximum value of signed char
SCHAR_MIN
-127
minimum value of signed char
SHRT_MAX
+32767
maximum value of short
SHRT_MIN
-32767
minimum value of short
UCHAR_MAX
255
maximum value of unsigned char
UINT_MAX
65535
maximum value of unsigned int
ULONG_MAX
4294967295
maximum value of unsigned long
USHRT_MAX
65535
maximum value of unsigned short
The names in the table below, a subset of <float.h>, are constants related to floating-point arithmetic. When a value is given, it represents the minimum magnitude for the corresponding quantity. Each implementation defines appropriate values.
FLT_RADIX
2
radix of exponent, representation, e.g., 2, 16
FLT_ROUNDS
floating-point rounding mode for addition
FLT_DIG
6
decimal digits of precision
FLT_EPSILON
1E-5
smallest number x such that 1.0+x != 1.0
FLT_MANT_DIG
number of base FLT_RADIX in mantissa
FLT_MAX
1E+37
maximum floating-point number
FLT_MAX_EXP
maximum n such that FLT_RADIXn-1 is representable
FLT_MIN
1E-37
minimum normalized floating-point number
FLT_MIN_EXP
minimum n such that 10n is a normalized number
DBL_DIG
10
decimal digits of precision
DBL_EPSILON
1E-9
smallest number x such that 1.0+x != 1.0
DBL_MANT_DIG
number of base FLT_RADIX in mantissa
DBL_MAX
1E+37
maximum double floating-point number
DBL_MAX_EXP
maximum n such that FLT_RADIXn-1 is representable
DBL_MIN
1E-37
minimum normalized double floating-point number
DBL_MIN_EXP
minimum n such that 10n is a normalized number