What is strategy pattern in Java?

What is a strategy class Java?

Strategy is a behavioral design pattern that turns a set of behaviors into objects and makes them interchangeable inside original context object. The original object, called context, holds a reference to a strategy object and delegates it executing the behavior.

What problem does strategy pattern solve?

Problem. The strategy pattern is used to solve problems that might (or is foreseen they might) be implemented or solved by different strategies and that possess a clearly defined interface for such cases.

What is Java Singleton pattern?

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. You can’t just use a class that depends on Singleton in some other context. …

Why is it called Strategy Pattern?

The idea behind the strategy pattern is that “algorithms can be selected at runtime.” (Wikipedia, Strategy Pattern) The pattern, in essence, is selecting the right strategy (or behavior) for solving a particular problem at runtime. Hence, it’s name.

What are the elements of strategy pattern?

The strategy pattern , which is sometimes called a policy pattern , consists of three basic components:

  • Strategy – A interfaced implementation of the core algorithm.
  • Concrete Strategy – An actual implementation of the core algorithm, to be passed to the Client .
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What is the benefit of strategy design pattern?

The Strategy Pattern has several advantages: It’s easy to switch between different algorithms (strategies) in runtime because you’re using polymorphism in the interfaces. Clean code because you avoid conditional-infested code (not complex).

What are the different design patterns?

There are five well-known design patterns possible to implement in a wide scope of programming languages:

  • Abstract Factory Pattern.
  • Builder Pattern.
  • Factory Method Pattern.
  • Prototype Pattern.
  • Singleton Pattern.

What is Visitor pattern in Java?

Visitor is a behavioral design pattern that allows adding new behaviors to existing class hierarchy without altering any existing code. Read why Visitors can’t be simply replaced with method overloading in our article Visitor and Double Dispatch.

What is the use of strategy design pattern in Java?

Essentially, the strategy pattern allows us to change the behavior of an algorithm at runtime. Typically, we would start with an interface which is used to apply an algorithm, and then implement it multiple times for each possible algorithm.

What is state pattern in Java?

State is a behavioral design pattern that allows an object to change the behavior when its internal state changes. The pattern extracts state-related behaviors into separate state classes and forces the original object to delegate the work to an instance of these classes, instead of acting on its own.