One example is “Functional programming with Java 8 functions,” in which author Edwin Dalorzo shows how to use lambda expressions and anonymous functions in Java 8. Architecture of a lambda.

It assumes the reader has experience programming in JavaScript. Functions as a map between two sets. A functional programmer views the nature of a function in a similar way as does a mathematician: It ...

For example, HashSet and HashMap do not maintain order and therefore using sort() on them doesn’t make sense. Streams and lambdas are an incredibly useful way to work with Java’s collections.

Java Supplier interface tutorial. As you can see, the code for the class that implements Java’s Supplier interface is fairly simple. The only requirements are the class declaration and the ...

Out of the three words, “pure” is the worst offender. I mean, “functional programming”¹ isn’t exactly well-defined, ... for example—and I consistently miss working in a pure language.

The advocates of functional programming say this is example of being able to catch an entire class of errors at compile time, leading to more predictable, reliable, and stable code. Figure 7 ...