38 lines
1.6 KiB
Markdown
38 lines
1.6 KiB
Markdown
---
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layout: pattern
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title: Strategy
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folder: strategy
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permalink: /patterns/strategy/
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categories: Behavioral
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tags:
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- Java
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- Difficulty-Beginner
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- Gang Of Four
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---
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## Also known as
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Policy
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## Intent
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Define a family of algorithms, encapsulate each one, and make them
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interchangeable. Strategy lets the algorithm vary independently from clients
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that use it.
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## Applicability
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Use the Strategy pattern when
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* many related classes differ only in their behavior. Strategies provide a way to configure a class either one of many behaviors
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* you need different variants of an algorithm. for example, you might define algorithms reflecting different space/time trade-offs. Strategies can be used when these variants are implemented as a class hierarchy of algorithms
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* an algorithm uses data that clients shouldn't know about. Use the Strategy pattern to avoid exposing complex, algorithm-specific data structures
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* a class defines many behaviors, and these appear as multiple conditional statements in its operations. Instead of many conditionals, move related conditional branches into their own Strategy class
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## Tutorial
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* [Strategy Pattern Tutorial](https://www.journaldev.com/1754/strategy-design-pattern-in-java-example-tutorial)
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## Credits
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* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)
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* [Functional Programming in Java: Harnessing the Power of Java 8 Lambda Expressions](http://www.amazon.com/Functional-Programming-Java-Harnessing-Expressions/dp/1937785467/ref=sr_1_1)
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