# modf : <math.h> library function

The function double modf(double x, double *intPart); breaks x into an integral and a fractional part. The fractional part is returned by the function and integral part is stored in object pointed by intPart pointer.

## Function prototype of modf

double modf(double x, double *intPart);
• x : A floating point number to break into parts.
• intPart : A pointer to an object where the integral part is stored.

## Return value of modf

It returns the fractional part of x. The fractional and integral part have the same sign as x.

## C program to show the use of modf function

The following program shows the use of modf function to break a floating point number into integral and fractional part.

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

int main ()
{
double x, integer, fraction;
printf("Enter a floating point number\n");
scanf("%lf", &x);

fraction = modf(x, &integer);
printf("Integer part of %lf : %lf\n", x, integer);
printf("Fractional part of %lf : %lf", x, fraction);

return 0;
}
```

Program Output
```Enter a floating point number
25.2345
Integer part of 25.234500 : 25.000000
Fractional part of 25.234500 : 0.234500
```