fabs-fabsf-fabsl.md

title	description	ms.date	api_name	api_location	api_type	topic_type	f1_keywords	helpviewer_keywords
fabs, fabsf, fabsl	API reference for fabs, fabsf, and fabsl; which calculate the absolute value of a floating-point value.	1/15/2021	fabsf fabs fabsl _o_fabs _o_fabsf	msvcrt.dll msvcr80.dll msvcr90.dll msvcr100.dll msvcr100_clr0400.dll msvcr110.dll msvcr110_clr0400.dll msvcr120.dll msvcr120_clr0400.dll ucrtbase.dll api-ms-win-crt-math-l1-1-0.dll	DLLExport	apiref	fabs fabsf fabsl mathabs mathabsf mathabsl	absolute values fabsf function calculating absolute values fabs function fabsl function

fabs, fabsf, fabsl

Calculates the absolute value of the floating-point argument.

Syntax

double fabs(
   double x
);
float fabs(
   float x
); // C++ only
long double fabs(
   long double x
); // C++ only
float fabsf(
   float x
);
long double fabsl(
   long double x
);

#define fabs(X) // Requires C11 or higher

Parameters

x
Floating-point value.

Return value

The fabs functions return the absolute value of the argument x. There's no error return.

Input	SEH exception	_matherr exception
± QNaN, IND	none	_DOMAIN

Remarks

C++ allows overloading, so you can call overloads of fabs if you include the <cmath> header. In a C program, unless you're using the <tgmath.h> macro to call this function, fabs always takes and returns a double.

If you use the fabs macro from <tgmath.h>, the type of the argument determines which version of the function is selected. See Type-generic math for details.

By default, this function's global state is scoped to the application. To change this behavior, see Global state in the CRT.

Requirements

Function	Required C header	Required C++ header
fabs, fabsf, fabsl	<math.h>	<cmath> or <math.h>
fabs macro	<tgmath.h>

For more compatibility information, see Compatibility.

Example

See the example for abs.

See also

Math and floating-point support
abs, labs, llabs, _abs64
_cabs