This pattern seems like a dynamic version of the Strategy pattern.

State Design Pattern is used to alter the behavior of an object when it’s internal state changes.

According to GoF definition, a state allows an object to alter its behavior when its internal state changes. State is a behavioral design pattern that allows an object to change the behavior when its internal state changes.. Then use if-else condition block to perform different actions based on the state. Being required to present both Fahrenheit degrees and Celsius degrees in the same application, thus making a form for each, is just a waste of time. In Strategy pattern, we create objects which represent various strategies and a context object whose behavior varies as per its strategy object. The design of an effective State Pattern requires the designer to make a list of possible states and relate each state with each other or we can say define a sequence of states to be changed. State Design Pattern is used to alter the behavior of an object when it’s internal state changes. Capture the abstraction in an interface, bury implementation details in derived classes. As far as I can tell they are 99% the same - the only difference being that the template method pattern has an abstract class as the base class whereas the strategy class uses an interface that is implemented by each concrete strategy class. This pattern is close to the concept of finite-state machines.The state pattern can be interpreted as a strategy pattern, which is able to switch a strategy through invocations of methods defined in the pattern's interface. Is there any way to minimize such wastage ? Both the Strategy design and State design has a structure that is similar between the two designs and depending on open structure. This article explains what is state pattern and how to implement state design pattern in C#. The strategy design encapsulates a various set of algorithms for runtime execution. The object will appear to change its class. If we see carefully the above State Design Pattern implementation, then we will found that there are many State objects created and destroyed. The strategy design encapsulates a various set of algorithms for runtime execution. In computer programming, the strategy pattern (also known as the policy pattern) is a behavioral software design pattern that enables selecting an algorithm at runtime. But it gives more flexibility. State pattern comes under behavioral design pattern category of Gang of four (GoF) design patterns. The state pattern is a behavioral design pattern. Hello Hans, There are many discussions on the difference in State and Strategy Pattern because both share the same class diagram. Hope this will help. In State pattern a class behavior changes based on its state. This pattern seems like a dynamic version of the Strategy pattern. The state pattern is a behavioral software design pattern that allows an object to alter its behavior when its internal state changes. In State pattern, we create objects which represent various states and a context object whose behavior varies as its state object changes. This type of design pattern comes under behavior pattern. In this pattern, an object is created which represent various states and a context object whose behavior varies as it's state object changes. There are also many other ways to implement a State Pattern. Similarities between State and Strategy Pattern If you look at UML diagram of State and Strategy design Pattern, they both look very similar to each other. One of the difference is that Context contains state as instance variable and there can be multiple tasks whose implementation can be dependent on the state whereas in strategy pattern strategy is passed as argument to the method and context object doesn’t have any variable to store it. In this pattern, an object is created which represent various states and a context object whose behavior varies as it's state object changes. Strategy lets the algorithm vary independently from clients that use it. The design of an effective State Pattern requires the designer to make a list of possible states and relate each state with each other or we can say define a sequence of states to be changed. In State pattern, we create objects which represent various states and a context object whose behavior varies as its state object changes. After reading the words above, I hope you have a good understanding of the differences between strategy pattern and state pattern. .NET Optimized code in C#. State pattern is useful when we want to maintain various states for a scenario in our program. This tutorial analyses Gang of Four’s Strategy Design Pattern versus State Design Pattern w.r.t to their similarities and differences. Since clients get exposed to implementation issues the strategy design pattern should be used only when the variation in behavior is relevant to them. Both the Strategy design and State design has a structure that is similar between the two designs and depending on open structure.