Unexpected output after typecasting

Asked Apr 05 '17 at 17:14

Active Apr 05 '17 at 17:14

Viewed 47 times

For the following print statement

std::cout << 10.1 / 0.1 << " " << (int)(10.1 / 0.1) << std::endl;

My understanding is that (10.1/0.1) is 101.0 hence after typecasting as an int the result should be 101. Instead I received 101 100. Can somebody please explain me why it is so???

asked Apr 05 '17 at 17:14

DhiwaTdG

It's because of floating point math. 0.1 is representable as a slightly larger number, and hence the result is slightly less than 101, so truncating will cut it off. – AndyG Apr 05 '17 at 17:17
Please also see this answer http://stackoverflow.com/a/16268154/27678 – AndyG Apr 05 '17 at 17:17
One possible hack is to add `0.5` to your floating point number then type-cast. As in `(int)(10.1 / 0.1 + 0.5)` – WhiZTiM Apr 05 '17 at 17:18
Possible duplicate of http://stackoverflow.com/q/588004/560648 – Lightness Races in Orbit Apr 05 '17 at 17:30

Unexpected output after typecasting

0 Answers0