Description: A functional interface in Java is a type of interface that contains exactly one abstract method. This concept is fundamental in functional programming, which has become increasingly relevant in modern software development. Functional interfaces allow developers to use lambda expressions and method references, simplifying code and improving readability. In Java 8, lambda expressions were introduced, enabling a more concise and expressive implementation of functional interfaces. This means that instead of creating anonymous classes to implement an interface, programmers can use a shorter and clearer syntax. Functional interfaces are particularly useful in the context of event-driven programming and in the use of collections, where operations like filtering, mapping, and reducing can be applied more efficiently. Additionally, functional interfaces can be used as first-class data types, allowing their use in various contexts where specific behavior is expected, such as in methods that accept functions as parameters. In summary, functional interfaces are a key feature of Java 8 that facilitates functional programming and enhances code clarity and conciseness.
