Singleton Pattern
At its core, the Singleton Pattern is about guaranteeing that there's only one instance of a class and providing a global point of access to that instance. It's like having a unique manager overseeing a particular aspect of your application, ensuring consistency and avoiding duplication of resources.
By following this pattern, we ensure that there's only one instance of the class throughout the application's lifecycle. This is particularly useful for managing shared resources, such as configuration settings, database connections, or logging mechanisms.
However, it's worth noting that while the Singleton Pattern provides global access to an instance, it can also introduce tight coupling and potential issues with testability. So, it's essential to weigh the benefits against the drawbacks and consider alternative patterns or architectural approaches when necessary.
Normal Traffic Signal
When you click on these traffic lights, they light up independently. This behaviour holds even when you add new instances of traffic lights.
Come on, try it out. Change the lights by clicking on them.
This pattern is often scalable as it can work independently of other instances since it does not share resources like configuration. However, if your application requires context to function appropriately, you may need to pass them every time you use its methods.
Singleton Traffic Signal
When you click on one of these traffic lights, it also updates the rest. This behaviour holds even when you add new instances of traffic lights, as we use the same instance of the traffic light.
This behaviour is due to the Singleton Pattern, which ensures that there is only one instance of the class throughout the app.
Some practical applications of the Singleton Pattern include building an SDK that requires initialization with some configuration. Once the user initializes the SDK, all its methods will have additional context from the configuration.