Hashcodes

[Beringer]

Does anybody know a good hashcode algorithm to generate unique codes? What if you have two objects and their properties are equal? How would a hashcode be unique then? Here, I am making an assumption that the hashcode is created using the properties of the control. So I guess the real question is: Is there a way to generate a unique hashcode that doesn't rely on the properties of the object? Thanks Eric

[Guffa]

Create a hashcode from the reference pointer. --- b { font-weight: normal; }

[Dan Neely]

Does the hashcode need to be unique/same across sessions? What're you using it for: uniqueness testing or sorting? If you don't need cross session consistancy or can save the code somehow, and are only using it for uniqueness testing: just give each object a guid.

[Ingo]

If you need a unique hashcode that doesn't depend on the properties try the timestamp instead or you can use guid instead of calculating them on your own. Greetings, Ingo

[Le centriste]

Be aware that if comparison of instances return true, like in:

obj1.Equal(obj2) == true

then they must return the same hashcode.

obj1.Hahscode() == obj2.hashcode()

So, if you implement your own hashcode that is unique for every instance, make sure to override the Equal method to always return false. If you don't do that, your class won't be usable in Arrays and Hashtables. -------- "I say no to drugs, but they don't listen." - Marilyn Manson

[Beringer]

Thanks for all the suggestions. Much appreciated. Eric