вычислить абсолютное значение целого числа (compute the absolute value of an integer)
Имя (Name)
abs, labs, llabs, imaxabs - compute the absolute value of an
integer
Синопсис (Synopsis)
#include <stdlib.h>
int abs(int j);
long labs(long j);
long long llabs(long long j);
#include <inttypes.h>
intmax_t imaxabs(intmax_t j);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
llabs():
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
Описание (Description)
The abs() function computes the absolute value of the integer
argument j. The labs(), llabs(), and imaxabs() functions compute
the absolute value of the argument j of the appropriate integer
type for the function.
Возвращаемое значение (Return value)
Returns the absolute value of the integer argument, of the
appropriate integer type for the function.
Атрибуты (Attributes)
For an explanation of the terms used in this section, see
attributes(7).
┌──────────────────────────────────────┬───────────────┬─────────┐
│Interface │ Attribute │ Value │
├──────────────────────────────────────┼───────────────┼─────────┤
│abs(), labs(), llabs(), imaxabs() │ Thread safety │ MT-Safe │
└──────────────────────────────────────┴───────────────┴─────────┘
Стандарты (Conforming to)
POSIX.1-2001, POSIX.1-2008, C99, SVr4, 4.3BSD. C89 only includes
the abs() and labs() functions; the functions llabs() and
imaxabs() were added in C99.
Примечание (Note)
Trying to take the absolute value of the most negative integer is
not defined.
The llabs() function is included in glibc since version 2.0. The
imaxabs() function is included in glibc since version 2.1.1.
For llabs() to be declared, it may be necessary to define
_ISOC99_SOURCE or _ISOC9X_SOURCE (depending on the version of
glibc) before including any standard headers.
By default, GCC handles abs(), labs(), and (since GCC 3.0)
llabs() and imaxabs() as built-in functions.
Смотри также (See also)
cabs(3), ceil(3), fabs(3), floor(3), rint(3)
