i dont know if i got your doubt or not but will say since the values +0.0 and -0.0 are identical or same so it returns true.............. if you have some other doubt do let us know please be specific with your doubt....?

In mathematical terms, +0.0 and -0.0 are the same, so that's why Java defines that comparison to return true. As you may know, it is true that +0.0 and -0.0 have different underlying bit representations, but you can't distinguish between them using the == operator.

However, the Double class does distinguish between the two, so this will print false: