Re: Hashtables

Roedy Green wrote: 

Someone could settle this point with a program that just kept doing a
toString() and hashCode on an array of objects and keep doing it to
see if they ever change.   (You must do something to create and
discard objects to trigger GC). I expect toString() will eventually
change after a GC but surely hashCode will not.

You may also see if there is a correlation between HashCode (dumped in
hex) and what toString() produces which is some sort of representation
of the address IIRC.


Probably.

"In other words, this method returns a string equal to the value of:

     getClass().getName() + '@' + Integer.toHexString(hashCode())"

http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Object.html#toString()

Just checking, Object.toString will use an overridden hashCode method.

I believe IBM JRE uses a different algorithm for creating hashCodes than Sun's. Sun's are predictable (or were), although they have changed their algorithm as well.

Tom Hawtin
--
Unemployed English Java programmer
http://jroller.com/page/tackline/
.

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