Contents
How is the strategy pattern defined?
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. Instead of implementing a single algorithm directly, code receives run-time instructions as to which in a family of algorithms to use.
Which of the following describes the builder pattern correctly?
Which of the following describes the Builder pattern correctly? This pattern builds a complex object using simple objects and using a step by step approach. This pattern refers to creating duplicate object while keeping performance in mind. This pattern is used when creation of object directly is costly.
Which of the following describes the Front Controller pattern correctly?
Q 16 – Which of the following describes the DAO pattern correctly? A – This pattern is used to separate low level data accessing API or operations from high level business services. B – This pattern is used to provide a centralized request handling mechanism so that all requests will be handled by a single handler.
Design Patterns – Strategy Pattern. In Strategy pattern, a class behavior or its algorithm can be changed at run time. This type of design pattern comes under behavior pattern. In Strategy pattern, we create objects which represent various strategies and a context object whose behavior varies as per its strategy object.
How are algorithms implemented in a strategy pattern?
Strategy enables the clients to choose the required algorithm, without using a “switch” statement or a series of “if-else” statements. Data structures used for implementing the algorithm are completely encapsulated in Strategy classes. Therefore, the implementation of an algorithm can be changed without affecting the Context class.
How is the strategy pattern used in Java?
The Strategy pattern lets you extract the varying behavior into a separate class hierarchy and combine the original classes into one, thereby reducing duplicate code. Use the pattern to isolate the business logic of a class from the implementation details of algorithms that may not be as important in the context of that logic.
How is the strategy pattern used in validation?
The validation algorithms (strategies), encapsulated separately from the validating object, may be used by other validating objects in different areas of the system (or even different systems) without code duplication . Typically, the strategy pattern stores a reference to some code in a data structure and retrieves it.