State pattern is used to change the behavior of an object when the state is changed. With the change in state, the behavior of that object is completely changed. This article demonstrates State pattern implementations in Java.
Observer pattern deals with state change between related objects. When one object depends on any state of another object, then when the state changes the dependent object needs to be notified. Observer pattern enables the dependent objects to subscribe to the state change of the subject object.
Observer pattern is used to automatically notify state change in object to all its dependent objects. It works as a pub/sub for state change between objects. This article demonstrates Observer pattern implementations in Java.
Memento pattern is responsible for maintaining the history of state change of an object. By keeping the history, Memento pattern ensures that we can check the object state history at any point, and also can revert any state change and move to the previous state.
Memento pattern is used to store the history of state changes of an object so that that history can be used to track back the change or be used for some other purpose. This article demonstrates Memento pattern implementations in Java.
Mediator pattern is used to restrict direct interaction between objects. A mediator class works as the middleman/communicator when one object wants to connect/use another object. This article demonstrates Mediator pattern implementations in Java.
Mediator pattern prevents direct interaction between objects and works as a middleman. As objects can not refer to another object directly in this pattern, that’s why it ensures loose coupling. In Mediator pattern, all communication between objects will be through the Mediator.
Iterator pattern is used when we need to traverse through a list of items. Iterator pattern hides the complexity of the iteration process and makes it easier to go through a list of items.
Iterator pattern is used to traverse and iterate through a list of items. This article demonstrates Iterator pattern implementations in Java.
Interpreter pattern is used when we need to represent some language expression or syntax in an Object-Oriented way. Like representing some logical operation or SQL syntax.Based on the implementation this design pattern can evaluate a specific language syntax, and provide the desired response.