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Re: Interchanging objects?

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Roedy Green wrote:
> Davej wrote, quoted or indirectly quoted someone who said :
> >I have been trying to think of a convenient way to interchange objects
> >that provide calculations that are done slightly differently. The
> >objects all have the same method names and return the same types. Is
> >there an elegant way to accomplish this? Thanks.
> 
> This is what an interface is for.  All the classes that perform the
> same operations but in a different way all implement the same
> interface.  Then you can refer to any objects of any of those classes
> by their interfacename.  What you call myinterface.calcBiggest for
> example, each object will uses its class's version of calcBiggest.
> 
> See http://mindprod.com/jgloss/interface.html

After you understand how interfaces work to encapsulate common types of 
behavior (as opposed to common implementations of behavior), you can use Java 7 
"closures" effectively. The Java version of closures is syntactic sugar for 
single-abstract-method (SAM) interfaces, that is, interfaces that define 
exactly one abstract method.

Example:

 public interface Closure
 {
   int performOp(int x, int y);
 }

The operations performed by 'performOp()' can be anything that operates on two 
'int' values and returns an 'int'.

-- 
Lew

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Interchanging objects? Davej <galt_57@hotmail.com> - 2012-02-04 12:02 -0800
  Re: Interchanging objects? Lew <lewbloch@gmail.com> - 2012-02-04 23:00 -0800
    Re: Interchanging objects? Davej <galt_57@hotmail.com> - 2012-02-05 07:41 -0800
      Re: Interchanging objects? Lew <lewbloch@gmail.com> - 2012-02-05 11:34 -0800
      Re: Interchanging objects? Roedy Green <see_website@mindprod.com.invalid> - 2012-02-08 22:42 -0800
        Re: Interchanging objects? Lew <lewbloch@gmail.com> - 2012-02-09 09:21 -0800
  Re: Interchanging objects? Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-02-07 08:09 -0500

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