Key Software Design Patterns Explained: Factory, Singleton, Observer, and More

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Design patterns are reusable, standardized solutions to recurring problems in software development, grouped into creational, structural, and behavioral categories. The Factory pattern separates object creation logic from usage, while the Singleton pattern ensures only one instance of a class exists for managing shared resources. The Observer pattern enables automatic updates to dependent objects when a subject's state changes, making it useful in reactive UI systems. The Decorator pattern lets developers add behaviors to individual objects dynamically without altering their core class. Other notable patterns include Facade, Strategy, Command, and Builder, each addressing distinct design challenges to improve code maintainability and scalability.

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