24 lines
784 B
Plaintext
24 lines
784 B
Plaintext
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= Singleton =
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A singleton is a design pattern in which a class has only one instance, and
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that instance is globally accessable. This is often important for use in shared
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resources, such as a file, database connection, or logging application.
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== Implementation ==
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* Make the default constructor private, preventing other objects from using
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`new`
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* Create a static creation method that acts as a constructor. This method calls
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a private constructor and instantiates a static field, which is the
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singleton. All further calls return a reference to this cached, static
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object.
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== Use case ==
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* strict control over global vars
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* instance where a single instance of an object is required
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== Cons ==
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* Take special care to not instantiate several in a multithreaded enviroment
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