How to extract the decimal part from a floating point number in C?

How can we extract the decimal part of a floating point number and store the decimal part and the integer part into two separate integer variables?

Solution 1:

You use the modf function:

double integral;
double fractional = modf(some_double, &integral);

You can also cast it to an integer, but be warned you may overflow the integer. The result is not predictable then.

Solution 2:

Try this:

int main() {
  double num = 23.345;
  int intpart = (int)num;
  double decpart = num - intpart;
  printf("Num = %f, intpart = %d, decpart = %f\n", num, intpart, decpart);
}

For me, it produces:

Num = 23.345000, intpart = 23, decpart = 0.345000

Which appears to be what you're asking for.