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Ali Samir
Ali Samir

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Understanding Design Patterns: Types and Definitions đź’ˇ

In software development, design patterns are proven solutions to common problems encountered in software design.

They provide a template for solving a problem in various contexts, making the development process more efficient and standardized.

This blog post will explore design patterns and their significance, and delve into the different types of design patterns with their definitions.


What Are Design Patterns?

Design patterns are reusable solutions to common problems in software design.

They represent best practices used by experienced object-oriented software developers.

Design patterns help in solving complex problems in a more manageable way, promoting code reuse, and making the design more flexible and robust.


Types of Design Patterns

Design patterns are typically categorized into three main types: Creational, Structural, and Behavioral.

Let's explore each of these types in detail.



đź“Ś1- Creational Design Patterns

Creational design patterns deal with object creation mechanisms. They try to create objects in a manner suitable to the situation.

The basic form of object creation could result in design problems or add complexity to the design.

Creational design patterns solve this problem by controlling the object-creation process.


⚡️Types of Creational Patterns:

  • Singleton: Ensures a class has only one instance and provides a global point of access to it.

  • Factory Method: Defines an interface for creating an object but lets subclasses alter the type of objects that will be created.

  • Abstract Factory: Provides an interface for creating families of related or dependent objects without specifying their concrete classes.

  • Builder: Separates the construction of a complex object from its representation so that the same construction process can create different representations.

  • Prototype: Specifies the kinds of objects to create using a prototypical instance, and creates new objects by copying this prototype.



đź“Ś2- Structural Design Patterns

Structural design patterns deal with object composition or how objects and classes can be combined to form larger structures.

These patterns help ensure that if one part of a system changes, the entire system doesn’t need to change as well.


⚡️Types of Structural Patterns:

  • Adapter: Allows incompatible interfaces to work together by converting the interface of a class into another interface the clients expect.

  • Decorator: Adds new behavior to objects dynamically without altering their structure.

  • Proxy: Provides a surrogate or placeholder for another object to control access to it.

  • Facade: Provides a simplified interface to a complex subsystem.

  • Bridge: Decouples an abstraction from its implementation so that the two can vary independently.

  • Composite: Composes objects into tree structures to represent part-whole hierarchies, allowing clients to treat individual objects and compositions uniformly.

  • Flyweight: Reduces the cost of creating and manipulating a large number of similar objects.



đź“Ś3- Behavioral Design Patterns

Behavioral design patterns deal with algorithms and the assignment of responsibilities between objects.

They help in defining how objects interact and communicate with each other.


⚡️Types of Behavioral Patterns:

  • Observer: Defines a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically.

  • Strategy: Defines a family of algorithms, encapsulates each one, and makes them interchangeable. Strategy lets the algorithm vary independently from clients that use it.

  • Command: Encapsulates a request as an object, thereby allowing users to parameterize clients with different requests, queue or log requests, and support undoable operations.

  • Chain of Responsibility: Passes a request along a chain of handlers, with each handler deciding either to process the request or pass it to the next handler in the chain.

  • Mediator: Defines an object that encapsulates how a set of objects interact, promoting loose coupling by preventing objects from referring to each other explicitly.

  • Memento: Without violating encapsulation, captures and externalizes an object’s internal state so that the object can be restored to this state later.

  • Template Method: Defines the skeleton of an algorithm in a method, deferring some steps to subclasses. It allows subclasses to redefine certain steps without changing the algorithm’s structure.

  • Visitor: Represents an operation to be performed on elements of an object structure, allowing new operations to be defined without changing the classes of the elements on which they operate.

  • State: Allows an object to alter its behavior when its internal state changes. The object will appear to change its class.



Conclusion âś…

Design patterns are an essential tool for any software developer, providing a proven solution to common problems and making code more robust and maintainable.

By understanding and applying the various types of design patterns—Creational, Structural, and Behavioral—you can enhance your software design skills and contribute to the development of high-quality software systems.

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