Design Patterns in Software Design

Design Patterns

Design patterns are reusable solutions to common problems that arise during software design.

Creational Patterns

• Deal with object creation mechanisms
• Focus on the creation of objects and how they are structured
• Examples:
  • Factory Pattern
  • Singleton Pattern
  • Abstract Factory Pattern
  • Builder Pattern

Behavioral Patterns

• Focus on the interactions between objects
• Define how objects communicate with each other
• Examples:
  • Observer Pattern
  • Strategy Pattern
  • Template Method Pattern
  • Iterator Pattern

Factory Pattern

• A creational pattern that provides a way to create objects without specifying the exact class of object
• Uses a factory method to create objects
• Advantages:
  • Encapsulates object creation
  • Reduces coupling between objects
  • Increases flexibility and scalability

Structural Patterns

• Focus on the composition of objects and how they are structured
• Define how objects are composed to form larger structures
• Examples:
  • Adapter Pattern
  • Bridge Pattern
  • Composite Pattern
  • Decorator Pattern

Singleton Pattern

• A creational pattern that ensures only one instance of a class is created
• Provides a global point of access to the instance
• Advantages:
  • Ensures only one instance is created
  • Provides a global point of access
  • Reduces memory usage
  • Improves performance

Design Patterns

• Reusable solutions to common software design problems

Creational Patterns

• Deal with object creation mechanisms and structure
• Examples:
  • Factory Pattern: provides a way to create objects without specifying the exact class
  • Singleton Pattern: ensures only one instance of a class is created
  • Abstract Factory Pattern: provides a way to create families of related objects
  • Builder Pattern: separates the construction of complex objects from their representation

Behavioral Patterns

• Focus on interactions between objects and how they communicate with each other
• Examples:
  • Observer Pattern: defines a one-to-many dependency between objects
  • Strategy Pattern: defines a family of algorithms and encapsulates each one
  • Template Method Pattern: provides a skeleton for algorithms and allows subclasses to customize it
  • Iterator Pattern: provides a way to access the elements of an aggregate object without exposing its underlying representation

Factory Pattern

• Creational pattern that encapsulates object creation and reduces coupling between objects
• Uses a factory method to create objects without specifying the exact class
• Advantages:
  • Encapsulates object creation
  • Reduces coupling between objects
  • Increases flexibility and scalability

Structural Patterns

• Focus on the composition of objects and how they are structured to form larger structures
• Examples:
  • Adapter Pattern: converts the interface of a class to match another interface
  • Bridge Pattern: separates an object's abstraction from its implementation
  • Composite Pattern: represents a group of objects as a single object
  • Decorator Pattern: adds additional responsibilities to an object without affecting other objects