Question to Pierre-Yves Saumont about Functional Programming in Java

[Mehman Ismayilov]

First thanks Pierre-Yves Saumont for writing such a book because for a long time i want to jump into world of Functional Programming using Java after my OCA Java 8 exam. For the exam i just learned and wrote a simple Lambda expressions that consumes a Lambda Predicate expression. Is this knowledge enough to start your book? Thanks and good luck with your future endeavors.

[Pierre-Yves Saumont]

Hi Mehman,

Sure, it is enough. Learning functional programming can be tough, but it is not related to how much you know about Java 8. You might however be surprised by the use of some features that are not often used, such as parameterized method call (but if you passed the OCA Java 8 exam, I guess you know this). Not a big deal anyway since although this is rarely used in traditional Java programming, it's not difficult to understand.

Beware however that functional programming has not much in common with what you learned for the OCA exam. In the book, you will write a library (through incremental exercises) while nearly never using a loop, or an if..else structure, or any other control structure. You will also nearly never use a non final "variable". And you will not use Java 8 functions: although the basic function you will define is nearly identical to the simplest form Function<A, B>, all others will be derived from this one. This is a book about thinking functional. It is not directly related to Java 8, although it will greatly help you write better Java 8 programs.