Data type constants are implementation-dependent ranges of values allowed for integral data types. The constants listed below give the ranges for the integral data types and are defined in LIMITS.H.
备注
The /J compiler option changes the default char type to unsigned.
Constant |
Value |
Meaning |
|---|---|---|
SCHAR_MAX |
127 |
Maximum signed char value |
SCHAR_MIN |
–128 |
Minimum signed char value |
UCHAR_MAX |
255 (0xff) |
Maximum unsigned char value |
CHAR_BIT |
8 |
Number of bits in a char |
USHRT_MAX |
65535 (0xffff) |
Maximum unsigned short value |
SHRT_MAX |
32767 |
Maximum (signed) short value |
SHRT_MIN |
–32768 |
Minimum (signed) short value |
UINT_MAX |
4294967295 (0xffffffff) |
Maximum unsigned int value |
ULONG_MAX |
4294967295 (0xffffffff) |
Maximum unsigned long value |
INT_MAX |
2147483647 |
Maximum (signed) int value |
INT_MIN |
–2147483647–1 |
Minimum (signed) int value |
LONG_MAX |
2147483647 |
Maximum (signed) long value |
LONG_MIN |
–2147483647–1 |
Minimum (signed) long value |
CHAR_MAX |
127 (255 if /J option used) |
Maximum char value |
CHAR_MIN |
–128 (0 if /J option used) |
Minimum char value |
MB_LEN_MAX |
2 |
Maximum number of bytes in multibyte char |
_I64_MAX |
9223372036854775807 |
Maximum (signed) __int64 value |
_I64_MIN |
-9223372036854775807-1 |
Minimum (signed) __int64 value |
_UI64_MAX |
0xffffffffffffffff |
Maximum (unsigned) __int64 value |
The following constants give the range and other characteristics of the double and float data types, and are defined in FLOAT.H:
Constant |
Value |
Description |
|---|---|---|
DBL_DIG |
15 |
# of decimal digits of precision |
DBL_EPSILON |
2.2204460492503131e-016 |
Smallest such that 1.0+DBL_EPSILON !=1.0 |
DBL_MANT_DIG |
53 |
# of bits in mantissa |
DBL_MAX |
1.7976931348623158e+308 |
Maximum value |
DBL_MAX_10_EXP |
308 |
Maximum decimal exponent |
DBL_MAX_EXP |
1024 |
Maximum binary exponent |
DBL_MIN |
2.2250738585072014e-308 |
Minimum positive value |
DBL_MIN_10_EXP |
(-307) |
Minimum decimal exponent |
DBL_MIN_EXP |
(–1021) |
Minimum binary exponent |
_DBL_RADIX |
2 |
Exponent radix |
_DBL_ROUNDS |
1 |
Addition rounding: near |
FLT_DIG |
6 |
Number of decimal digits of precision |
FLT_EPSILON |
1.192092896e-07F |
Smallest such that 1.0+FLT_EPSILON !=1.0 |
FLT_MANT_DIG |
24 |
Number of bits in mantissa |
FLT_MAX |
3.402823466e+38F |
Maximum value |
FLT_MAX_10_EXP |
38 |
Maximum decimal exponent |
FLT_MAX_EXP |
128 |
Maximum binary exponent |
FLT_MIN |
1.175494351e-38F |
Minimum positive value |
FLT_MIN_10_EXP |
(–37) |
Minimum decimal exponent |
FLT_MIN_EXP |
(–125) |
Minimum binary exponent |
FLT_RADIX |
2 |
Exponent radix |
FLT_ROUNDS |
1 |
Addition rounding: near |