Suppose we have two Die variables d1 and d2. Can the method invocation d1.roll() affect the state of d2 if d1 == d2? What if d1 != d2? If two objects are equal in the sense of ==, are they...

Suppose we have two Die variables d1 and d2. Can the method invocation d1.roll() affect the state of d2 if d1 == d2? What if d1 != d2?

If two objects are equal in the sense of ==, are they automatically equal in the sense of equals()? What about vice versa?