Math.sqrt()

[Usha Vydyanathan]

Hi,
Check following code.
class test
{
public static void main(String [] args) {
System.out.println(Math.sqrt(-0));
System.out.println(Math.sqrt(+0));
System.out.println(Math.sqrt(-0.0));
System.out.println(Math.sqrt(+0.0));
}
}
prints
0.0,
0.0
-0.0
0.0
Why Math.sqrt(-0) differs from Math.sqrt(-0.0)?
Thanks,
Usha

[Cindy Glass]

0.0 is a double. Both floats and doubles suffer from imprecision when operated on. You can only guarantee that the answer will be CLOSE to that number. To be truely acurrate they would have to have an infinite number of decimal places - not likely.
So when you take a square root of -0.0 you get something CLOSE to 0, but whatever variance there is is in the negative direction.