Question on HashSet

[Dinesh Tahiliani]

import java.util.HashSet;
public class test6 
{ /** * @param args */
int count;
test6(int s)
{count =s;
}
public static void main(String[] args) 
{// TODO Auto-generated method stub
HashSet<test6> set=new HashSet<test6>();
set.add(new test6(5));
set.add(new test6(5));
set.add(new test6(3));

for (test6 t: set)
System.out.println("Set contains --" + t.count);
}
public boolean equals(Object o)
{
if((o==null)&&(!(o instanceof test6) ))
{
return false;
}
return (this.count== ((test6)o).count);
}
public int hashcode()
{
return count;
}

}

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 ..

[Vlado Zajac]

You have to override hashCode() method (with capital C).

[Dinesh Tahiliani]

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]

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