Numeric limits
From cppreference.com
Contents |
[edit] 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) |
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) |
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) |
[edit] Example
Run this code
#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 = 4294967295
[edit] Limits of integer types
Defined in header
<limits.h> |
|
CHAR_BIT |
number of bits in 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_MIN
SHRT_MIN INT_MIN LONG_MIN LLONG_MIN (C99)
|
minimum value of signed char, short, int, long and long long respectively (macro constant) |
SCHAR_MAX
SHRT_MAX INT_MAX LONG_MAX LLONG_MAX (C99)
|
maximum value of signed char, short, int, long and long long respectively (macro constant) |
UCHAR_MAX
USHRT_MAX UINT_MAX ULONG_MAX ULLONG_MAX (C99)
|
maximum value of unsigned char, unsigned short, unsigned int, unsigned long and unsigned long long respectively (macro constant) |
[edit] Example
Run this code
#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 = 18446744073709551615
[edit] Limits 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)
|
number of decimal digits that can be converted to long double and back without losing precision (macro constant) |
FLT_MIN DBL_MIN LDBL_MIN |
minimum, normalized, positive value of float, double and long double respectively (macro constant) |
FLT_MAX DBL_MAX LDBL_MAX |
maximum value of float, double and long double respectively (macro constant) |
FLT_EPSILON DBL_EPSILON LDBL_EPSILON |
difference between 1.0 and the next representable value for float, double and long double respectively (macro constant) |
FLT_DIG DBL_DIG LDBL_DIG |
number of decimal digits that can be represented without losing precision for float, double and long double respectively (macro constant) |
FLT_MANT_DIG DBL_MANT_DIG LDBL_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_EXP DBL_MIN_EXP LDBL_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_EXP DBL_MIN_10_EXP LDBL_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_EXP DBL_MAX_EXP LDBL_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_EXP DBL_MAX_10_EXP LDBL_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, equal to float_round_style (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_SUBNORM
DBL_HAS_SUBNORM LDBL_HAS_SUBNORM (C11)
|
whether the type supports subnormal (denormal) numbers: -1 indeterminable, 0 absent, 1 present (macro constant) |
[edit] Example
Run this code
#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 = 1