Strategy Pattern

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Strategy Pattern

• Parul Patel
• Josh Goodrich
• Justin Plotkin
• Jonas Wei

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Purpose of Strategy Pattern

• Encapsulate different algorithms
• Strategy lets the alogorithm vary independantly
  from the clients that use it.
• The Strategy pattern defines an abstract policy
  for performing an algorithm At the same time it
  provides multiple mechanisms that can comply with
  that policy, thus letting mechanism vary
  independently from the policy required.

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Use When

• You have many related classed that differ only in
  their behavior.
• You need different variants of an algorithm.
• An algorithm uses data that clients shouldn't
  know about.
• It helps to avoid exposing complex,
  algorithm-specific data structures.
• When you have several conditional statements in
  the program.

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Strategy Pattern Example 1
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Strategy Pattern Example 2
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Benefits

• Families of related algorithms
• An alternative to subclassing
• Easier to vary algorithm
• Removes hard-wiring
• Strategies eliminate conditional statements.

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Drawbacks

• The application must be aware of all the
  strategies to select the right one for the right
  situation.
• Increased number of object
• Context and the Strategy classes normally
  communicate through the interface