Calculates the floating-point remainder.

double fmod( 
   double x,
   double y 
);
float fmod(
   float x,
   float y 
);  // C++ only
long double fmod(
   long double x,
   long double y
);  // C++ only
float fmodf( 
   float x,
   float y 
);

Parameters

x, y

Floating-point values.

Return Value

fmod returns the floating-point remainder of x / y. If the value of y is 0.0, fmod returns a quiet NaN. For information about representation of a quiet NaN by the printf family, see printf.

Remarks

The fmod function calculates the floating-point remainder f of x / y such that x = i * y + f, where i is an integer, f has the same sign as x, and the absolute value of f is less than the absolute value of y.

C++ allows overloading, so you can call overloads of fmod. In a C program, fmod always takes two doubles and returns a double.

Requirements

For additional compatibility information, see Compatibility in the Introduction.

Libraries

All versions of the C run-time libraries.

Example

// crt_fmod.c
/* This program displays a floating-point remainder.
 */

#include <math.h>
#include <stdio.h>

int main( void )
{
   double w = -10.0, x = 3.0, z;

   z = fmod( w, x );
   printf( "The remainder of %.2f / %.2f is %f\n", w, x, z );
}

Output

The remainder of -10.00 / 3.00 is -1.000000

See Also

Floating-Point Support Routines | ceil | fabs | floor | Run-Time Routines and .NET Framework Equivalents