<Li> The abstract factory, builder, and prototype patterns can use singletons in their implementation . </Li> <Li> Facade objects are often singletons because only one facade object is required . </Li> <Li> State objects are often singletons . </Li> <Li> Singletons are often preferred to global variables because: <Ul> <Li> They do not pollute the global namespace (or, in languages with namespaces, their containing namespace) with unnecessary variables . </Li> <Li> They permit lazy allocation and initialization, whereas global variables in many languages will always consume resources . </Li> </Ul> </Li>

When do you use the singleton pattern in oops