Numeric limits
Limits of library types
Defined in header <stdint.h>
|
|
|---|---|
|
PTRDIFF_MIN (C99) |
minimum value of object of ptrdiff_t type(macro constant) |
|
PTRDIFF_MAX (C99) |
maximum value of object of ptrdiff_t type(macro constant) |
|
SIZE_MAX (C99) |
maximum value of object of size_t type(macro constant) |
|
SIG_ATOMIC_MIN (C99) |
minimum value of object of sig_atomic_t type(macro constant) |
|
SIG_ATOMIC_MAX (C99) |
maximum value of object of sig_atomic_t type(macro constant) |
|
WINT_MIN (C99) |
minimum value of object of wint_t type(macro constant) |
|
WINT_MAX (C99) |
maximum value of object of wint_t type(macro constant) |
Defined in header <wchar.h>
|
|
|
WCHAR_MIN (C99) |
minimum value of object of wchar_t type(macro constant) |
|
WCHAR_MAX (C99) |
maximum value of object of wchar_t type(macro constant) |
Example
#include <stdio.h>
#include <stdint.h>
#include <wchar.h>
int main(void)
{
printf("PTRDIFF_MIN = %td\n", PTRDIFF_MIN);
printf("PTRDIFF_MAX = %+td\n", PTRDIFF_MAX);
printf("SIZE_MAX = %zu\n", SIZE_MAX);
printf("SIG_ATOMIC_MIN = %+jd\n",(intmax_t)SIG_ATOMIC_MIN);
printf("SIG_ATOMIC_MAX = %+jd\n",(intmax_t)SIG_ATOMIC_MAX);
printf("WCHAR_MIN = %+jd\n",(intmax_t)WCHAR_MIN);
printf("WCHAR_MAX = %+jd\n",(intmax_t)WCHAR_MAX);
printf("WINT_MIN = %jd\n", (intmax_t)WINT_MIN);
printf("WINT_MAX = %jd\n", (intmax_t)WINT_MAX);
}Possible output:
PTRDIFF_MIN = -9223372036854775808
PTRDIFF_MAX = +9223372036854775807
SIZE_MAX = 18446744073709551615
SIG_ATOMIC_MIN = -2147483648
SIG_ATOMIC_MAX = +2147483647
WCHAR_MIN = -2147483648
WCHAR_MAX = +2147483647
WINT_MIN = 0
WINT_MAX = 4294967295Limits of integer types
Defined in header <limits.h>
|
|
|---|---|
|
CHAR_BIT |
number of bits in a byte (macro constant) |
|
MB_LEN_MAX |
maximum number of bytes in a multibyte character (macro constant) |
|
CHAR_MIN |
minimum value of char(macro constant) |
|
CHAR_MAX |
maximum value of char(macro constant) |
|
SCHAR_MINSHRT_MININT_MINLONG_MINLLONG_MIN (C99) |
minimum value of signed char, short, int, long and long long respectively(macro constant) |
|
SCHAR_MAXSHRT_MAXINT_MAXLONG_MAXLLONG_MAX (C99) |
maximum value of signed char, short, int, long and long long respectively(macro constant) |
|
UCHAR_MAXUSHRT_MAXUINT_MAXULONG_MAXULLONG_MAX (C99) |
maximum value of unsigned char, unsigned short, unsigned int,
|
Example
#include <stdio.h>
#include <limits.h>
int main(void)
{
printf("CHAR_BIT = %d\n", CHAR_BIT);
printf("MB_LEN_MAX = %d\n", MB_LEN_MAX);
printf("\n");
printf("CHAR_MIN = %+d\n", CHAR_MIN);
printf("CHAR_MAX = %+d\n", CHAR_MAX);
printf("SCHAR_MIN = %+d\n", SCHAR_MIN);
printf("SCHAR_MAX = %+d\n", SCHAR_MAX);
printf("UCHAR_MAX = %u\n", UCHAR_MAX);
printf("\n");
printf("SHRT_MIN = %+d\n", SHRT_MIN);
printf("SHRT_MAX = %+d\n", SHRT_MAX);
printf("USHRT_MAX = %u\n", USHRT_MAX);
printf("\n");
printf("INT_MIN = %+d\n", INT_MIN);
printf("INT_MAX = %+d\n", INT_MAX);
printf("UINT_MAX = %u\n", UINT_MAX);
printf("\n");
printf("LONG_MIN = %+ld\n", LONG_MIN);
printf("LONG_MAX = %+ld\n", LONG_MAX);
printf("ULONG_MAX = %lu\n", ULONG_MAX);
printf("\n");
printf("LLONG_MIN = %+lld\n", LLONG_MIN);
printf("LLONG_MAX = %+lld\n", LLONG_MAX);
printf("ULLONG_MAX = %llu\n", ULLONG_MAX);
printf("\n");
}Possible output:
CHAR_BIT = 8
MB_LEN_MAX = 16
CHAR_MIN = -128
CHAR_MAX = +127
SCHAR_MIN = -128
SCHAR_MAX = +127
UCHAR_MAX = 255
SHRT_MIN = -32768
SHRT_MAX = +32767
USHRT_MAX = 65535
INT_MIN = -2147483648
INT_MAX = +2147483647
UINT_MAX = 4294967295
LONG_MIN = -9223372036854775808
LONG_MAX = +9223372036854775807
ULONG_MAX = 18446744073709551615
LLONG_MIN = -9223372036854775808
LLONG_MAX = +9223372036854775807
ULLONG_MAX = 18446744073709551615Limits of floating point types
Defined in header <float.h>
|
|
|---|---|
|
FLT_RADIX |
the radix (integer base) used by the representation of all three floating-point types (macro constant) |
|
DECIMAL_DIG (C99) |
conversion from long double to decimal with at least DECIMAL_DIG digits and back to long double is the identity conversion: this is the decimal precision required to serialize/deserialize a long double(macro constant) |
|
FLT_DECIMAL_DIGDBL_DECIMAL_DIGLDBL_DECIMAL_DIG (C11) |
conversion from float/double/long double to decimal with at least FLT_DECIMAL_DIG/DBL_DECIMAL_DIG/LDBL_DECIMAL_DIG digits and back is the identity conversion: this is the decimal precision required to serialize/deserialize a floating point value. Defined to at least 6, 10, and 10 respectively, or 9 for IEEE float and 17 for IEEE double. (see also the C++ analog max_digits10)(macro constant) |
|
FLT_MINDBL_MINLDBL_MIN |
minimum, normalized, positive value of float, double and long double respectively(macro constant) |
|
FLT_TRUE_MINDBL_TRUE_MINLDBL_TRUE_MIN (C11) |
minimum positive value of float, double and long double respectively(macro constant) |
|
FLT_MAXDBL_MAXLDBL_MAX |
maximum value of float, double and long double respectively(macro constant) |
|
FLT_EPSILONDBL_EPSILONLDBL_EPSILON |
difference between 1.0 and the next representable value for float, double and long double respectively(macro constant) |
|
FLT_DIGDBL_DIGLDBL_DIG |
number of decimal digits that are guaranteed to be preserved in text -> float/double/long double -> text roundtrip without change due to rounding or overflow (see the C++ analog digits10 for detail)(macro constant) |
|
FLT_MANT_DIGDBL_MANT_DIGLDBL_MANT_DIG |
number of base-FLT_RADIX digits that are in the floating-point mantissa and that can be represented without losing precision for float, double and long double respectively(macro constant) |
|
FLT_MIN_EXPDBL_MIN_EXPLDBL_MIN_EXP |
minimum negative integer such that FLT_RADIX raised by power one less than that integer is a normalized float, double and long double respectively(macro constant) |
|
FLT_MIN_10_EXPDBL_MIN_10_EXPLDBL_MIN_10_EXP |
minimum negative integer such that 10 raised by power one less than that integer is a normalized float, double and long double respectively(macro constant) |
|
FLT_MAX_EXPDBL_MAX_EXPLDBL_MAX_EXP |
maximum positive integer such that FLT_RADIX raised by power one less than that integer is a normalized float, double and long double respectively(macro constant) |
|
FLT_MAX_10_EXPDBL_MAX_10_EXPLDBL_MAX_10_EXP |
maximum positive integer such that 10 raised by power one less than that integer is a normalized float, double and long double respectively(macro constant) |
| rounding mode of floating-point arithmetics (macro constant) | |
|
(C99) |
use of extended precision for intermediate results: 0 not used, 1 double is used instead of float, 2: long double is used(macro constant) |
|
FLT_HAS_SUBNORMDBL_HAS_SUBNORMLDBL_HAS_SUBNORM (C11) |
whether the type supports subnormal (denormal) numbers: -1 indeterminable, 0 absent, 1 present (macro constant) |
Example
#include <stdio.h>
#include <float.h>
#include <math.h>
int main(void)
{
printf("FLT_RADIX = %d\n", FLT_RADIX);
printf("DECIMAL_DIG = %d\n", DECIMAL_DIG);
printf("FLT_MIN = %e\n", FLT_MIN);
printf("FLT_MAX = %e\n", FLT_MAX);
printf("FLT_EPSILON = %e\n", FLT_EPSILON);
printf("FLT_DIG = %d\n", FLT_DIG);
printf("FLT_MANT_DIG = %d\n", FLT_MANT_DIG);
printf("FLT_MIN_EXP = %d\n", FLT_MIN_EXP);
printf("FLT_MIN_10_EXP = %d\n", FLT_MIN_10_EXP);
printf("FLT_MAX_EXP = %d\n", FLT_MAX_EXP);
printf("FLT_MAX_10_EXP = %d\n", FLT_MAX_10_EXP);
printf("FLT_ROUNDS = %d\n", FLT_ROUNDS);
printf("FLT_EVAL_METHOD = %d\n", FLT_EVAL_METHOD);
printf("FLT_HAS_SUBNORM = %d\n", FLT_HAS_SUBNORM);
}Possible output:
FLT_RADIX = 2
DECIMAL_DIG = 37
FLT_MIN = 1.175494e-38
FLT_MAX = 3.402823e+38
FLT_EPSILON = 1.192093e-07
FLT_DIG = 6
FLT_MANT_DIG = 24
FLT_MIN_EXP = -125
FLT_MIN_10_EXP = -37
FLT_MAX_EXP = 128
FLT_MAX_10_EXP = 38
FLT_ROUNDS = 1
FLT_EVAL_METHOD = 1
FLT_HAS_SUBNORM = 1See also
© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
http://en.cppreference.com/w/c/types/limits
