### 1.19 `fabs`, `fabsf`—absolute value (magnitude) ¶

Synopsis

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

Description
`fabs` and `fabsf` calculate the absolute value (magnitude) of the argument x, by direct manipulation of the bit representation of x.

Returns
The calculated value is returned. No errors are detected.

Portability
`fabs` is ANSI. `fabsf` is an extension.