Strategy Design Pattern

1
Strategy Design Pattern

• B.Ramamurthy

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Strategy

• Often there are alternative ways or strategies to
  achieve a goal.
• These strategies are usually realized using
  algorithms.
• Only one of them may be used depending on the
  context.
• The algorithms representing the strategies can be
  encapsulated each in a class.
• Strategy pattern itself represents a collection
  of these alternative ways in a hierarchy of
  classes, each class representing an alternative.

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Strategy Design
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Examples

• Different layouts for graphical components
  (JFrame, JPanel, JApplet)
• Checkout counter software has TaxCalculator
  class. Depending on the place (context) the tax
  computation differs.
• Mr.Xs strategies in the ScotlandYard game.

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Mr.X and Strategy Design Pattern
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Layout Example