Visual Studio 6.0

Calculates the floating-point remainder.

double fmod( double x, double y );

Function Required Header Compatibility
fmod <math.h> ANSI, Win 95, Win NT

For additional compatibility information, see Compatibility in the Introduction.


LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Import library for MSVCRT.DLL, retail version

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.


x, y

Floating-point values


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.


/* FMOD.C: This program displays a
 * floating-point remainder.

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

void main( void )
   double w = -10.0, x = 3.0, y = 0.0, z;

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



The remainder of -10.00 / 3.00 is -1.000000

Floating-Point Support Routines

See Also   ceil, fabs, floor