fabs() — Calculate Floating-Point Absolute Value

Format

#include <math.h>
double fabs(double x);

Language Level: ANSI

Threadsafe: Yes.

Description

The fabs() function calculates the absolute value of the floating-point argument x.

Return Value

The fabs() function returns the absolute value. There is no error return value.

Example that uses fabs()

This example calculates y as the absolute value of x:

#include <math.h>
#include <stdio.h>
 
int main(void)
{
   double x, y;
 
   x = -5.6798;
   y = fabs(x);
 
   printf("fabs( %lf ) = %lf\n", x, y);
}
 
/*******************  Output should be similar to:  ***************
 
fabs( -5.679800 ) = 5.679800
*/

Related Information

• abs() — Calculate Integer Absolute Value
• labs() — llabs() — Calculate Absolute Value of Long and Long Long Integer
• <math.h>