C Language Standard Math Double precision floating-point remainder: fmod()
Example
This function returns the floating-point remainder of the division of x/y. The returned value has the same sign as x.
#include <math.h> /* for fmod() */
#include <stdio.h> /* for printf() */
int main(void)
{
double x = 10.0;
double y = 5.1;
double modulus = fmod(x, y);
printf("%lf\n", modulus); /* f is the same as lf. */
return 0;
}
Output:
4.90000
Important: Use this function with care, as it can return unexpected values due to the operation of floating point values.
#include <math.h>
#include <stdio.h>
int main(void)
{
printf("%f\n", fmod(1, 0.1));
printf("%19.17f\n", fmod(1, 0.1));
return 0;
}
Output:
0.1
0.09999999999999995
