Functional Programming in Java

Appendix A. Using Java 8 functional features

When Java 8 was released, it was presented by Oracle as a step towards more-functional programming. Among the functional-friendly features listed in Oracle’s “What’s New in JDK 8” note were the following:

• “Lambda Expressions, a new language feature, has been introduced in this release. They enable you to treat functionality as a method argument, or code as data. Lambda expressions let you express instances of single-method interfaces (referred to as functional interfaces) more compactly.” This is a very important aspect of the functional paradigm.
• “Method references provide easy-to-read lambda expressions for methods that already have a name.” The latter part of that sentence probably refers to ...