Reference
C Library
IOstream Library
Strings library
STL Containers
STL Algorithms
Miscellaneous
C Library
cassert (assert.h)
cctype (ctype.h)
cerrno (errno.h)
cfloat (float.h)
ciso646 (iso646.h)
climits (limits.h)
clocale (locale.h)
cmath (math.h)
csetjmp (setjmp.h)
csignal (signal.h)
cstdarg (stdarg.h)
cstddef (stddef.h)
cstdio (stdio.h)
cstdlib (stdlib.h)
cstring (string.h)
ctime (time.h)
cmath (math.h)
functions:
abs
acos
asin
atan
atan2
ceil
cos
cosh
exp
fabs
floor
fmod
frexp
ldexp
log
log10
modf
pow
sin
sinh
sqrt
tan
tanh
macro constants:
HUGE_VAL


fabs

function
<cmath> 
     double fabs (      double x );
      float fabs (       float x );
long double fabs ( long double x );

Compute absolute value

Returns the absolute value of x ( /x/ ).

In C++, abs is also declared in this header with the same behavior.

Parameters

x
Floating point value.

Return Value

The absolute value of x.

Portability

In C, only the double version of this function exists with this name.

Example

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/* fabs example */
#include <stdio.h>
#include <math.h>
int main ()
{
  printf ("The absolute value of 3.1416 is %lf\n", fabs (3.1416) );
  printf ("The absolute value of -10.6 is %lf\n", fabs (-10.6) );
  return 0;
}


Output:

The absolute value of 3.1416 is 3.141600
The absolute value of -10.6 is 10.600000

See also

abs Absolute value (function)
labs Absolute value (function)
floor Round down value (function)
ceil Round up value (function)
modf Break into fractional and integral parts (function)