java documentation for Double.equals(Object) says as follows
Note that in most cases, for two instances of class Double, d1 and d2, the value of d1.equals(d2) is true if and only if
d1.doubleValue() == d2.doubleValue()
also has the value true. However, there are two exceptions:
If d1 and d2 both represent Double.NaN, then the equals method returns true, even though Double.NaN==Double.NaN has the value false.
If d1 represents .0 while d2 represents -0.0, or vice versa, the equal
test has the value false, even though .0==-0.0 has the value true.
This definition allows hash tables to operate properly.
Hope your doubt is clear
Sanyev
