fabs(), fabsf(), fabsl() — Calculate floating-point absolute value

Standards

Standards / Extensions	C or C++	Dependencies
ISO C POSIX.1 XPG4 XPG4.2 ISO/ANSI C++ C99 Single UNIX Specification, Version 3 C++ TR1 C99	both

Format

#include <math.h>

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);

General description

The fabs() functions calculate the absolute value of a floating-point argument.

Note: These functions work in both IEEE Binary Floating-Point and hexadecimal floating-point formats. See IEEE binary floating-point for more information about IEEE Binary Floating-Point.

Returned value

Returns the absolute value of the float input.

Example

/* This example calculates y as the absolute value of x. */
#include <math.h>

int main(void)
{
   double x, y;

   x = -5.6798;
   y = fabs(x);

   printf("fabs( %f ) = %f\n", x, y);
}

Output

fabs( -5.679800 ) = 5.679800