Error with division using double type in Java

Question

Okay. I have been bashing my head against the wall for like 2 hours now trying to figure out why in the world double answer = 364/365; is telling me that answer is 0. Or any other combination of double for that matter, its just truncating the decimal and I just don't know why.

Answer 1

364/365 performs integer division (truncates the decimal).

Try double answer = 364.0/365; to force it to perform floating point division.

Something like:

double days_in_year = 365;
double answer = 364/days_in_year;

would work as well, since one of the operands isn't an integer.

Answer 2

You're taking an int type (364) and dividing by another int type (365) - the answer is going to be an int. This is then stored in a double type answer. You could do the following:

double answer = 364d / 365d;

More info here:

http://mindprod.com/jgloss/division.html