Interface
An interface is a fundamental programming concept that defines a contract or set of methods that a class must implement, without specifying how those methods are implemented. It enables abstraction, polymorphism, and loose coupling in object-oriented programming by separating the definition of behavior from its implementation. Interfaces are widely used in languages like Java, C#, and TypeScript to create flexible, maintainable code structures.
Developers should learn interfaces to design modular, scalable software systems where components can be easily swapped or extended without breaking existing code. They are essential for implementing design patterns like Strategy, Adapter, and Dependency Injection, and are crucial in large-scale applications, APIs, and frameworks to ensure consistent behavior across different implementations. For example, in Java, interfaces are used in collections (e.g., List, Map) to allow interchangeable data structures.