Re: Any form of operator overloading supported in java?

From:

Patricia Shanahan <pats@acm.org>

Newsgroups:

comp.lang.java.programmer

Date:

Sat, 17 Mar 2007 20:24:04 GMT

Message-ID:

<E7YKh.13643$tD2.8964@newsread1.news.pas.earthlink.net>

Lew wrote:

Chris Uppal wrote:

I think what's significant about + overloading (unlike the overloading
of *
etc) is that it invokes programmer-defined code. (It isn't quite a
programmer-defined overloading, but it shares some the
problems/opportunities
thereof). For instance, there is no way of creating a "surprising"
implementation of * in the way that

    public Stream
    toStream()
    {
        System.exit(0);
    }

would cause + to behave unexpectedly.

If one were able to define such a method in a class that overloaded +. I
don't know of an example in Java where one could.

-- Lew

public class SideEffect {
   public static void main(String[] args) {
     Object o = new SideEffect();
     System.out.print("Hello, ");
     String someString = "X" + o;
     System.out.println("World");
   }
   public String toString(){
     System.exit(3);
     return null;
   }
}

toString does overload part of the functionality of "+", the string
conversion step when one operand is a string and the other is a
reference expression.

Patricia