Difference between revisions of "Singleton"
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*If an instance already exists, it simply returns a reference to that object. | *If an instance already exists, it simply returns a reference to that object. | ||
*To make sure that the object cannot be instantiated any other way, the constructor is made either private or protected. | *To make sure that the object cannot be instantiated any other way, the constructor is made either private or protected. | ||
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| + | ==UML Diagram== | ||
| + | [[Image:Singleton_UML.png]] | ||
Revision as of 17:59, 8 March 2007
Introduction
Singleton pattern Ensure a class only has one instance, and provide a global point of access to it. This is useful when exactly one object is needed to coordinate actions across the system.
Implementation
- Singleton pattern is implemented by creating a class with a method that creates a new instance of the object if one does not exist.
- If an instance already exists, it simply returns a reference to that object.
- To make sure that the object cannot be instantiated any other way, the constructor is made either private or protected.
UML Diagram
