so i have a question on hashcode() and equals() method  Let's say I just write a very basic program overridng both the methodes  import java.util.*;  class Employee {    private String name;    private int empid;      public Employee(String name,int empid)    {        this.name=name;        this.empid=empid;    }      public int getEmpid()    {        return empid;    }      public String getName()    {        return name;    }      public boolean equals(Object obj)    {        System.out.println("equals has just been called...");        Employee e1=(Employee)obj;        return ((name.equals(e1.name)) &amp;&amp; (empid==e1.empid));    }      public int hashCode()    {        System.out.println("hashcode called...");        return empid;    }  }   Then, let's say I write another class to add and iterate the elements in HashSet  class Five {    public static void main(String args[])    {        HashSet hs1=new HashSet();        hs1.add(new Employee("Alex",25));        hs1.add(new Employee("Peter",25));        hs1.add(new Employee("Martin",25));        hs1.add(new Employee("Alex",25));          Iterator itr=hs1.iterator();         while(itr.hasNext())        {            Employee e=(Employee)itr.next();            System.out.println(e.getEmpid()+"\t"+e.getName());        }       }  }   now the question is  when i try to add Alex again with the same empid the equals() always called thee times  as there is no index n hashmap so in case if it first be checked with previously added Alex it will return true and should not be called for the other two elements (peter and martin) but equals always called 3 times  why..??  is objects within same bucket do also have the index..??
What issues / pitfalls must be considered when overriding equals and hashCode?
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