Common Uses
- The Abstract Factory, Builder, and Prototype patterns can use Singletons in their implementation.
- Facade Objects are often Singletons because only one Facade object is required.
- State objects are often Singletons.
- Singletons are often preferred to global variables because:
- They do not pollute the global name space (or, in languages with namespaces, their containing namespace) with unnecessary variables.
- They permit lazy allocation and initialization, whereas global variables in many languages will always consume resources.
Read more about this topic: Singleton Pattern
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