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Updates in Kotlin for Developers series

In the last few months, I made several important changes in the books from the Kotlin for Developers series. Let's summarize them all.


Throughout the past half a year, I was adding exercises to the books from the series, except for Effective Kotlin: Best Practices (to stick to the original concept of the book, however, its exercises can be found in the ebook Kotlin Exercises).

This is the number of exercises in each book:

I published ebook Kotlin Exercises that includes all the exercises from the series. In its TOC you can find exercises from all the books.


Many people asked me for sources of code snippets from the books. I decided to publish them. You can find autogenerated (so always up-to-date) sources of all the books from the series in the following repositories:

In those repositories you can find code snippets in markdown files related to each chapter, and all executable code in the src directory, in packages corresponding to the chapters.

Book samples

Now all books from the series have free samples available on LeanPub. You can find them on the book pages:

Smaller margins and font size

Some books from the series started being a bit too large in paperback, especially after I added exercises and solutions. This was especially a problem with Kotlin Coroutines: Deep Dive, that would have nearly 600 pages (it reads fast, as there is planty of code inside). Though, the margins and the font size still gave me space for saving some pages. So I changed margin sizes (top 0.75'', bottom 0.75'', inner 0.75'', outer 0.5'') and font size (9.5pt). This change made the book more comfortable to read and saved some pages. There is also another big benefit of this change: One of my biggest problems is that paperback limits width of the code. This change allowed me to increase the width of the code, from 62 characters to 67 (that few characters help a lot), which means that more snippets can have more intuitive formatting.

Consistent structure

I changed the structure of the books to make them more consistent. Many subchapters become chapters, and subsections become subchapters. Levels are the same for all books from the series. This change makes the books more consistent and easier to navigate.

I also extracted parts in the book Advanced Kotlin to make it more consistent with the rest of the series. However, I decided to keep Kotlin Essentials and Functional Kotlin flat. So first two books in the series are flat, and the last three are divided into parts.

Consistent introduction and ending

I overviewed all the books and made sure that the introduction and ending are consistent. I also added a few new paragraphs to the introduction of each book, to make it more clear what the book is about and what the reader can expect from it.

New Kotlin features

Underscore operator for type arguments, data objects, ushr function... All the most recent changes in Kotlin are already included in the books from the series. I constantly update the books to make sure they are up-to-date.

Suggestions and corrections

Is there anything more I should do? Let me know if you have any suggestions or corrections. I am always happy to improve the books. My email is

Getting updated books

If you purchased the books from the series on LeanPub, you can always download the most recent version of the book. If you purchased the books from the series on Amazon, if you Tweet a photo of the book with @ktdotacademy, we will send you a coupon code for the second edition of the ebook on LeanPub.