Learn about common design patterns as reusable solutions to software design problems.
Design patterns are well-documented, reusable solutions to common problems that arise during software design. They are not specific algorithms or pieces of code, but rather general concepts and templates that describe how to structure classes and objects to solve a particular problem in a flexible and maintainable way. They represent the distilled experience of many software developers over many years. Design patterns are typically categorized into three groups. **Creational Patterns** deal with object creation mechanisms, trying to create objects in a manner suitable to the situation. Examples include the Singleton (ensuring a class has only one instance) and Factory Method (creating objects without specifying the exact class of object that will be created). **Structural Patterns** deal with object composition, or how to assemble objects and classes into larger structures. Examples include the Adapter (allowing incompatible interfaces to work together) and Decorator (adding new functionality to an object dynamically). **Behavioral Patterns** are concerned with communication between objects. Examples include the Observer (defining a one-to-many dependency between objects so that when one object changes state, all its dependents are notified) and Strategy (defining a family of algorithms, encapsulating each one, and making them interchangeable). Learning design patterns provides you with a shared vocabulary and a toolkit of proven solutions, helping you avoid reinventing the wheel and enabling you to build more sophisticated and robust software architectures.