There are actually a bunch of different kinds of functions you can use in lambda expressions in Java 8 (43, to be exact). https://www.tutorialspoint.com/java8/

There are actually a bunch of different kinds of functions you can use in lambda expressions in Java 8 (43, to be exact). https://www.tutorialspoint.com/java8/java8_functional_interfaces.htm https://www.tutorialspoint.com/java8/java8_functional_interf... Beyond that, by at least 1.4 you could pass methods using the reflections API, though that was kludgy in a lot of ways.