Re: Distinct ID Number Per Object?
Mark Thornton <mark.p.thornton@ntl-spam-world.com> writes:
While the objects address may be unique (amongst objects existing at a
given time), the value returned by System.identityHashCode is NOT
guaranteed to be unique. Indeed in some cases it couldn't be. The
hashCode is a 32 bit integer, but a 64 bit VM could have more than 2^32
objects, in which case some of those objects would have the same hash code.
I am somewhat disappointed, that no one has yet
reported about results from the program I posted in
<identityHashCode-20070616191650@ram.dialup.fu-berlin.de>
public class Main
{ final static java.lang.String lineSeparator =
java.lang.System.getProperty( "line.separator" );
public static void main( final java.lang.String[] args )
{ final java.lang.Object object = new java.lang.Object();
final int code = object.hashCode();
java.lang.Object object1;
int code1;
do
{ code1 =( object1 = new java.lang.Object() ).hashCode(); }
while( code1 != code );
java.lang.System.out.print
(( object == object1 )+ lineSeparator +
code + lineSeparator +
code1 + lineSeparator ); }}
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