Providing a hash key which may be used for object identification, for example in
Hashtable and Map
of the Collections Framework/API
(http://java.sun.com/products/jdk/1.2/docs/guide/collections/).
This is explained in the java.lang.Object section of the API documentation. Try doing
your own
work next time.
--- abhay <[EMAIL PROTECTED]> wrote:
> Hello,
>
> Just a small doubt. Has anybody ever used hashCode() ... the
> java.lang.Object provides ?
> To be honest i dont know how to use this in our applications .
> (Can anybody suggest any way to use hashCode() ? )
>
> The API says ...
>
> "As much as is reasonably practical, the hashCode method defined by
> class Object does return distinct integers for distinct objects. (This
> is typically implemented by converting the internal address of the
> object into an integer, but this implementation technique is not
> required by the JavaTM programming language.) "
>
> So can we safely assume that its the address of the object in memory ?
> (a pointer in C or C++)
> So if java a developer need not be concerned about pointers, what is
> this method doing here ?
>
> What is more striking is that the API says ..
> "If two objects are equal according to the equals(Object) method, then
> calling the hashCode method on each of the two objects must produce the
> same integer result"
>
> This means if you have a two objects with equal values inside (for
> instance ..
> String str1 = new String("Abhay");
> String str2 = new String("Abhay");
>
> and if hashCode() returns the address then does it means that these 2
> objects are physically one and
> the same in the memory ? I dont get it ...
>
> Please share your knowledge..
>
> Thanks.
>
> regards
> abhay kulkarni
>
>
>
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>
=====
Mark Zawadzki Performance Engineer/DBA/Programmer extraordinaire� [EMAIL PROTECTED]
[EMAIL PROTECTED]
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