🚀 go-pugleaf

Pete Blacker wrote:
> 
> Hi
> 
> I've done some simple Applet programing in Java, and I've decided to
> start doing some serious work now. I haven't found any comprehensive
> information on OOP in java anywhere. So I still have a very simple
> question unanswered. Does Java support multiple inheritance, if so I
> could use a quick trivial example. I'm not new to OOP but I am new to
> java.
> Thanks for you help, in advance.
> 
> Pete Blacker

The first thing to say about multiple inheritance is that its use often
indicates that IS-A and HAS-A has been confused -- that is an aeroplane
doesn't inherit from Fuselage and Wings.

Here's an example of MI of interfaces taken from Arthur J. Riel's book
'Object Oriented Design Heuristics', a useful book.

interface WoodenObject {
	public void burn();
	public int getDensity();
}

interface Door {
	public void open();
	public void close();
}

class WoodenDoor implements WoodenObject, Door {
...
}

Of course you might already have an implementation of Door (called
DoorImpl, say)
So you might do:

class WoodenDoor extends Door implements WoodenObject {
...
}

Tom