hashCode( )

[Maureen Charlton]

I have the following output:

JOHN DOE : Java
Calculated hash=4 for JOHN DOE
students[hash]: JOHN DOE : Java
students hashCode value = 21990827

Could someone explain why I got the hashCode value = 21990827 and NOT 4? (4 is what I was expecting?

 
         students [hash] = studentDetails[lp];
         System.out.println ("students[hash]  :  "+students[hash] + "  students hashCode value =  "+ students[hash].hashCode( ) );
 

Do I need to have a toString( ) method? Similar to when I wish to have something more meaningful when printing out the contents of an array?

Thanking you in advance!

[Ernest Friedman-Hill]

You need to override hashCode() in Student. If you wanted the hashCode() for a Student object to be the same as the hashCode() for the Student's name, then you could write

class Student {
  private String _name;
  public int hashCode() {
    return _name.hashCode();
  }
}