Functional Programming, Simplified (a best-selling FP book)

Functional Programming, Simplified — currently 5-star rated on, 4.5-star rated on Amazon, and one of the all-time best-selling books on functional programming — is currently on sale in three formats (prices shown in USD):

PDF Format
$15 on

PDF version of Functional Programming, Simplified

Paperback Book
Now $29.99 on Amazon

Print version of Functional Programming, Simplified

Kindle eBook
$14.99 on Amazon

Kindle version of Functional Programming, Simplified

Please note that the Amazon rankings would be almost 5.0, except that we had some early printing problems that have since been fixed.

About the book versions

If you like e-books, the PDF is probably the best version of the book because I can control the formatting and it contains all of the lessons. The Kindle version also contains the entire book, but I can’t control the formatting as well.

Please note that because of size considerations I had to omit a few lessons from the paperback version of the book, so I made those lessons available online for free.

Why buy Functional Programming, Simplified?

A great reason to buy Functional Programming, Simplified is because I tried to take the best ideas from the books on the right side of this image and include them in the one book on the left:

Functional Programming, Simplified vs many other FP books

In my own case I had to spend weeks reading all of those books on the right — plus hundreds of additional blog posts — to try to understand functional programming (FP). To save you a lot of time and frustration, my hope is that you’ll only need to read the book on the left to understand functional programming in Scala.

Programming languages (Scala, Kotlin, Java)

The book is written using Scala, but because Scala and Kotlin are similar, it may also be helpful for Kotlin programmers. Because Scala runs on the Java Virtual Machine (JVM) and derives from Java — and because thousands of developers are learning Scala — I think it will also be helpful to Java programmers.

Free previews!

If you’d like to preview the book before buying it, see this page for free preview options for Functional Programming, Simplified.

One more thing

I’m glad to say this:

2% of the profits from the book will be donated to The Scala Center.

This is a small way to “pay it forward,” and show my gratitude to the creators of the Scala programming language and the Scala community.