A class implements an interface by appending Java’s implements keyword followed by a comma-separated list of interface names to the class header, and by coding each interface method in the class.

class java.util.ArrayList class java.util.LinkedList In this case, the implementation methods for ArrayList, LinkedList, and Vector are all different, which is a great scenario for using an interface.

So a more concise lambda expression that implements this Java Function interface would look like this: Function<Integer, String> conciseLambda = (Integer x)-> { return Integer.toString(x*x); }; System ...