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Functional programming with java
Functional Programming is a programming paradigm that focuses on the use of functions and the application of mathematical techniques to solve problems. Java, being an object-oriented programming language, is not fully functional, but it has incorporated functional programming features in its latest versions.
One of the main features of Functional Programming in Java is the ability to treat functions as first-class objects. This means that functions can be passed as arguments to other functions, returned as function results, and stored in variables.
Next, I explain the key aspects of functional programming in Java:
Functions as first-class citizens: In Java, functions are treated as first-class objects, which means they can be assigned to variables, passed as arguments to other functions, and returned as the result of a function. This allows functions to be treated like any other data type.
Lambda Expressions: A lambda expression is a concise way of representing an anonymous function. In Java, the lambda expression syntax was introduced in version 8, making it easier to write functions inline. Lambda expressions are especially useful in functional programming, as they allow you to pass functions as arguments to other functions in a more compact way.
Functional interfaces: Java 8 also introduced the concept of functional interfaces, which are interfaces that contain a single abstract method. These interfaces are used to represent function types and can be used in combination with lambda expressions. Some predefined functional interfaces in Java include Predicate, Function, Consumer, and Supplier.
Reference methods: Reference methods are a way to reference existing methods instead of writing a new lambda expression for them. This makes the code more readable and reduces duplication. There are different types of method references, such as a static method reference, an instance method reference, and a constructor reference.
- Streams: Streams are one of the most powerful features of functional programming in Java. A stream is a sequence of elements that are processed functionally. Streams allow you to perform operations such as filtering, mapping, sorting, and reducing on a collection of data in a declarative and concurrent manner.