Header File 

math.h  

Category 

Math Routines 

Prototype 

double modf(double x, double *ipart); 

long double modfl(long double x, long double *ipart); 

Description 

Splits a double or long double into integer and fractional parts. 

modf breaks the double x into two parts: the integer and the fraction. modf stores the integer in ipart and returns the fraction. 

modfl is the long double version; it takes long double arguments and returns a long double result. 

Return Value 

modf and modfl return the fractional part of x. 

Example  

#include <math.h>
#include <stdio.h>
int main(void)
{
    double fraction, integer;
    double number = 100000.567;
    fraction = modf(number, &integer);
    printf("The whole and fractional parts of %lf are %lf and %lf\n",
           number, integer, fraction);
    return 0;
}

Portability