Singleton in PHP

Singleton is a creational design pattern, which ensures that only one object of its kind exists and provides a single point of access to it for any other code. Singleton has almost the same pros and cons as global variables. Although they’re super-handy, they break the modularity of your code. You can’t just use a class that depends on a Singleton in some other context, without carrying over the Singleton to the other context. Most of the time, this limitation comes up during the creation of unit tests.

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