Kotlin Programming: The Big Nerd Ranch Guide, First Edition

For the More Curious: Lambdas vs Anonymous Inner Classes

If you have not used function types before, you may wonder why you would want to use them in your program. Our answer: Function types offer increased flexibility with less boilerplate. Consider a language that does not offer function types, like Java 8.

Java 8 includes support for object-oriented programming and lambda expressions but does not include the ability to define a function as a parameter to a function or variable. Instead, Java provides anonymous inner classes – nameless classes that are defined within another class to implement a single method definition. You can pass anonymous inner classes as an instance, like a lambda. For example, in Java 8, to pass the definition ...