Method references: A primer My previous Java 101 tutorial introduced lambda expressions, which are used to define anonymous methods that can then be treated as instances of a functional interface.

Get a deep dive into using method references in your Java programs, including stream operations, event listeners, and constructors and factories.

Implementation of the UnaryOperator example To show you an old school, pre-Java 8 UnaryOperator example, we will create a single class named UnaryOperatorExample and provide the required apply method.