Understanding Interface Types in Java for Cleaner Code

Day 57 of 100 Days of Java — Interface Types in Java In Java, an interface defines a contract of methods that must be implemented by the classes using it. there are different types of interfaces in Java based on their method structure and purpose 1.Normal Interface A regular interface containing one or more abstract methods. Used when: Multiple methods need to be implemented by different classes. 2.Functional Interface An interface with exactly one abstract method (can have multiple default/static methods). Annotated with @FunctionalInterface. SAM Interface(Single Abstract Method)another name for a Functional Interface. Used mainly with Lambda Expressions and Streams API. Used for: Lambda expressions and functional programming Introduced in Java 8. 3.Marker Interface An empty interface (no methods at all). It gives metadata to JVM or compiler. Examples: Serializable, Cloneable, Remote Used for: Providing special information or behavior to the class. Key Takeaways Interfaces promote abstraction and loose coupling. Functional Interfaces enable modern Java functional programming. Marker Interfaces communicate intent to JVM. My Learning Reflection Understanding different interface types helped me write cleaner, modular, and more reusable Java code. Each type has a unique role in real-world applications — from designing APIs to using Lambda expressions efficiently. 🧵 #100DaysOfJava #JavaLearning #FunctionalInterfaces #OOPsInJava #CodingJourney

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