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Kotlin in Action

4.44  ·  Rating details ·  401 ratings  ·  37 reviews
Kotlin is a new programming language targeting the Java platform. It offers on expressiveness and safety without compromising simplicity, seamless interoperability with existing Java code, and great tooling support. Because Kotlin generates regular Java bytecode and works together with existing Java libraries and frameworks, it can be used almost everywhere where Java is u ...more
ebook, Manning Publications, 360 pages
Published May 2016 by Manning Publications
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Regis Hattori
Mar 25, 2020 rated it it was amazing
Shelves: programming
Very complete, focused on its differences compared to other languages not just in terms of syntax but also in terms of patterns. Because it was written by one of the designers of the language is very useful because he explains the decisions they made and you can understand the "why"s.

In the Generics chapter, there is the better explanation I ever read about invariants, covariants, and contravariants.

DSL chapter is very useful to understand how the majority of Kotlin libs work. It is much better
Wang Zirui
Nov 02, 2018 rated it did not like it
I don't like the book. It keeps saying Java is bad. I was trained in Java and I don't think the authors are making the right points. Java is a great language in my opinion, while Kotlin looks more like a bunch of ad hoc ideas. It's less elegant than Java. But the fact is that my colleagues are using Kotlin and I have to learn it. I'm looking for a better book that shows basic respect for Java. ...more
Andrei Catinean
Oct 21, 2016 rated it it was amazing
Great book for anyone who wants to start grasping Kotlin. Goes from basic knowledge and use cases to rather complex ones towards the end.

There is a fair assumption that you are familiar with Java, as the book does not cover basic Java or object oriented programming explanations.
Nickson Kaigi
* 3.5 stars
* Must Have, if you intend to pass the Coursera course: Kotlin for Java Developers.
* This book was written in 2017 for Kotlin 1.0. When I read it, Kotlin was in version 1.3. Still a good book.

Exactly what you would expect from the people who worked at JetBrains to develop the Kotlin language.

Not beginner friendly, but goes in-depth with the language features. Has excellent comparisons between how Java does things vs the Kotlin way.

Loved reading part 2 of the book: Embracing Kotlin. Th
Mark Nenadov
Feb 20, 2018 rated it really liked it
This book takes an excellent approach to teaching the Kotlin language and I highly recommend it to anyone who wants to dive into it. I enjoyed the way it is contrasted and compared to Java. I did find the sledding to be slow towards the end, though.
Muhammad Hakim Asy'ari
Aug 25, 2017 rated it really liked it
The best book for developer start coding in kotlin
Antonel Pazargic
Sep 24, 2017 rated it it was amazing
Shelves: kotlin
I really enjoyed the way the book is written.
The authors found out a way to present the cool Kotlin features to make them easy to grasp.
The only thing that I found out quite hard to keep the pace with was the last part in the kotlin reflection (json parsing and object deserialization).
I am already looking forward to seeing the 2nd version of Kotlin in Action - including probably the kotlin coroutines, KJS.
Mingwei Zhang
Jul 13, 2017 rated it really liked it
It is a very good introductory book on Kotlin. I would recommend anyone with some Java background to read it and try out Kotlin.
Michael Greifeneder
Dec 09, 2017 rated it it was amazing
Shelves: own
Just for the wonderful explanation of Generics I would recommend that book.
Jul 22, 2018 rated it it was amazing
This should be your first Kotlin book provided you have a good grasp programming concepts.

It is a brisk, no-nonsense, and pretty exhaustive coverage of the features of Kotlin. Unlike programming books that introduce a new language, this book does not go over the basics concepts of OO. Instead, it assumes you know your programming concepts (at least OO) and starts by describing how they are supported in Kotlin. For concepts common to Java, the book 1) briskly describes the concept as it occurs i
Aug 10, 2019 rated it really liked it
The book teaches Kotlin from the perspective of a skilled Java programmer.
It clearly separates topics into chapters but language aspects are often described insofar as they differ from Java.
Explanations are clear and generally easy to follow.
It cannot be used as a reference.

The book also pays a lot of attention to Java compatibility.
When Kotlin language features are explained the authors always indicate how Kotlin compiles those features into Java bytecode and how Java code can access code compi
Jan 15, 2020 rated it really liked it
Loved it. I’ve worked with Java and Groovy for years and some time ago started Kotlin. Book gave me insights into concepts that I kind of used but did not understand them thoroughly.
Useful bits for me:
- objects are for singleton use
- extension functions are a thing, the ones with receiver types are useful in DSLs, also extension functions can be defined inside of a class
- generics, variance - now its clear what those “in” an “out” next to generic types mean
- operator overloading is something I’d
Piotr Kalinowski
May 21, 2017 rated it it was amazing
Shelves: computers
Very no-nonsense and straightforward presentation style tailored for experienced programmers. I didn't feel like I have to skip through most of the book. It really focused on introducing new JVM language instead of teaching programming.

I liked how it took the time to explain a few implementation details, so that the reader could immediately understand how various language features interact with Java. But the authors didn't stop at that and also included some notes on how performance may be affec
Elliot Jean
Jan 23, 2020 rated it really liked it
An excellent book for developers to know more about Kotlin. It assumes some Java experience for the readers. If you haven't already known some Kotlin before, I'd say this book is perfect for you to get started.

I already knew some Kotlin and would like to delve more into the advanced topics. So I skimmed through the first half of the book which is the foundations and focused on the second half explaining the type system, lambda, DSL, reflections of Kotlin.

Overall I found the author explaining wit
Rostislav Vatolin
This is a perfect book to read, if you want to start with Kotlin, all the main features are explained here. As said in the back cover, the authors are expecting you to have experience with Java, it is true, so if you only starting you programming career, this book wouldn't be a smooth read for you. There is no doubt that it will boost your performance if you're only starting with kotlin, so I really recommend it to read before you start some serious complex stuff with this language.
I really than
Marcos Trujillo
Jul 27, 2017 rated it it was amazing
This is the perfect book to learn Kotlin (if you have already experience programming, of course)
It's a trip to understand almost all the features kotlin has, inciting not only in the well know features like nullability or Higher order functions, also in the core parts of kotlin and, more important, in the whys and hows.
With this book you have also access to a complete set of exercices and examples similar to Kotlin Koans.

If you are planing to develop in Kotlin this is your book.

Yamir Encarnacion
This is a great book to learn Kotlin if you already know Java. If you do not know Java, many things will probably be confusing. The books starts off with the basics and works its way towards more advanced topics.

Also, it is a lot to take in from one reading. Myself, I expect to re-read this book.
Feb 13, 2019 rated it it was amazing
Excellent overview of the Kotlin programming language. Starts with the fundamentals and works up to higher level constructs at a great pace. I found the chapter on DSLs most useful. It illustrates the power of lambdas with receivers and extension functions and should further help you understand Kotlin DSLs in the wild.
Dmytro Chasovskyi
Oct 31, 2019 rated it it was amazing
Shelves: technical
As the book states, it will work the best for those who want to see Kotlin features and move from other JVM-based languages like Java.

I definitely recommend it for people who consider switching to Kotlin but beware that it is not easy and relaxed reading. I found it hard to understand some ideas the way they described here.
Ricardo Hernández
Jul 11, 2020 rated it really liked it
Excellent book to get into Kotlin essentials. Please note this is not a hands-on book that guides you through the language using exercises and examples. Mostly of the contents are theory on the
Logical programming of Kotlin (authors are part of team behind JetBrains).

Good resource as a jumpstart from Java to Kotlin.
Jul 29, 2017 rated it it was amazing
Shelves: programming
Good introduction to Kotlin for Java developers
Justin Smith
Jan 02, 2018 rated it liked it
Not very engaging but it will give you a grasp of some deep Kotlin concepts if you don't fall asleep first. ...more
Łukasz Słonina
Feb 03, 2019 rated it liked it
Very good book about Kotlin, you should know Java in details to take most of this book.
Apr 20, 2019 rated it really liked it
Shelves: programming
Great introduction to Kotlin. However occasionally too verbose and occasionally not explaining enough.
Siarhei Krukau
Don't get me wrong, I'm a huge fan of Kotlin. But this book is too boring and hard-to-read. ...more
Felipe Albuquerque
Oct 29, 2019 rated it really liked it
Great introduction to Kotlin. The examples are easy to understand and follow, and the comparisons with the Java codes generated for the JVM make it easier for Java developers to make the transition.
Dmytro Turskyi
Jan 11, 2020 rated it it was ok
Shelves: programming
I think this book is obviously is useful for those who are going to use Kotlin, though the real practical information you can take from it is quite doubtful. It is pretty dry and outdated.
Apr 13, 2020 rated it it was amazing
Well written, concise and to the point. Language features are corroborated by nice examples. However, covers Kotlin 1.0 (and parts of 1.1). Thus, features such as coroutines are not covered.

The book is as good as some other Manning publications I read. Made me order a few more. :)
Aug 05, 2020 rated it really liked it
A great intro to Kotlin, written for java developers
Tianyao Chen
Nov 15, 2020 rated it it was amazing
Shelves: tech-books
A fantastic Kotlin book! Dives deeper than Header First Kotlin. I would recommend read this book after Header First Kotlin:DD
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