When to use the Observer design pattern?ĭevelopers widely use the Observer design pattern, where many objects depend on a particular object. Whenever an event is triggered, all the observers catch it and make the relevant changes. All the observers wait for a certain event to trigger. This pattern defines a one-to-many relationship, i.e., many objects depend upon a particular object. It is often used in event-driven programming, where an event can trigger a change in state in one or more other objects.
The Observer design pattern is a behavioral pattern that defines a one-to-many relationship between objects, such that one object (the subject) can notify other objects (the observers) of changes to its state. The Gang of Four (GoF) proposed the 23 design patterns to speed up the development process and provide well-tested development paradigms. They provide a way of solving a particular problem in the most sophisticated way. The design patterns provide the programmers with a solution to a recurring programming problem.
