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Question on HashSet

Dinesh Tahiliani
Ranch Hand

Joined: Aug 06, 2007
Posts: 486


output :
Set contains --5
Set contains --5
Set contains --3

Why its returning me tow times 5 , i have used the equals and hashcode also.
Can anyone help me out ..



Thanks<br />Dinesh
Vlado Zajac
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Joined: Aug 03, 2004
Posts: 245
You have to override hashCode() method (with capital C).
Dinesh Tahiliani
Ranch Hand

Joined: Aug 06, 2007
Posts: 486
Sorry my mistake:

Thanks for correcting.

If i pass null set.put(null), it gives me NullPointer Expection, i know nullponter means its trying to refer th object with null reference in memory.
Correct me if iam wrong
bart zagers
Ranch Hand

Joined: Feb 05, 2003
Posts: 234
I guess you want '||' in your equals method instead of '&&'.

You get the NullPointerException on the line
System.out.println("Set contains --" + t.count);
You get null from the Set, so t == null, so t.count gives you the exception.
So you don't get the exception in the setting, but in the getting
 
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