Object.hashCode() algorithm

java hashcode pseudocode
Roam picture Roam · Jul 31, 2013 · Viewed 8.6k times · Source

I'm looking for the algorithm of Object.hashCode().

This code is native in Object.java.

Is this because

(a) the code is in assembly-- never was in Java or any other HLL at all

or

(b) it simply isn't disclosed

?

In either case, I am looking to get hold of the algorithm (pseudo-code or some detailed explanation) of "how hashCode() is calculated"-- what are the params going into its calculation and the calculation itself?

Please note: It's the hashCode() of Object i'm looking for-- not another like that of String or hashMap/table.

//==========================================================================

the new Java docs-- jdk 8 now saying 

"The value returned by hashCode() is the object's hash code, which is the object's memory address in hexadecimal."

Answer

nkukhar picture nkukhar · Jul 31, 2013

Native hashCode method implementation depends on the JVM. By default in HotSpot it returns random number, you can check it in the source code (function get_next_hash)

Related questions

How can I generate an MD5 hash?

Is there any method to generate MD5 hash of a string in Java?

Read More
What issues should be considered when overriding equals and hashCode in Java?

What issues / pitfalls must be considered when overriding equals and hashCode?

Read More
Why do I need to override the equals and hashCode methods in Java?

Recently I read through this Developer Works Document. The document is all about defining hashCode() and equals() effectively and correctly, however I am not able to figure out why we need to override these two methods. How can I take …

Read More