Method Call

[Pervez Amin]

Can somebody please explain this one in detail please.

class Super
{
  public String toString()
  {

     return "4";
  }
}
public class SubClass extends Super
{
  public String toString()
  {

     return super.toString()+"3";
  }
  public static void main(String[] args)
  {
    [B]System.out.println( new SubClass() );[/B]
  }
}

I don't understand the syntax in bold. How does it know to call the toString(). If you have more than one method will "new SubClass();" call them all. Can someone pls explain how this is working.

(Marilyn added code tags)
[This message has been edited by Marilyn deQueiroz (edited November 04, 2001).]

[Marilyn de Queiroz]

The System.out.println() method is overloaded to accept Objects as well as Strings (and various primitives) and can therefore deal with this new SubClass() object. See this API page for more details.

What did you see when you ran this program?

new SubClass() will create an instance of SubClass. It does not call any methods.
[This message has been edited by Marilyn deQueiroz (edited November 04, 2001).]

[rajashree ghatak]

System.out.println( new SubClass() );
in the above statement,new SubClass()statement is creating an object of the class SubClass.when an object is passed in print or println staements as an argument,toString() method of that class is called implicitly.
Here System.out.println( new SubClass() );
is equivalent to System.out.println( new SubClass().toString() );
which calls the toString() of SubClass which in turn calls toString() method of Super through super.toString() call.
The output is "43"
HTH
rajashree.

[Pervez Amin]

Thanx Rajashree,
I undersand now!!