Design Patterns discussion

[Peter Horan <peter AT deakin.edu.au>]

Chris Finlayson wrote:

> To me, a more confusing example is State versus Strategy.  I finally
> decided that if I would implement it with a set of inner class, then it
> was an example of the State pattern.  Otherwise, it was a likely
> candidate for the Strategy pattern.  By that distintion, obviously, only
> the one outer class can use the State inner-classes, while the Strategy
> pattern can be shared between different classes."

These patterns have the same class and object structure.

The difference is that in strategy, the selected strategy is usually set 
from outside, and is unlikely to change, whereas in the state pattern, 
the selected state object changes frequently as defined by the state 
model in response to the current state and received events.
--
Peter Horan                     School of Information Technology
peter AT deakin.edu.au
             Deakin University
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