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

Question

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?

Answer 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.