Introduction - If you have any usage issues, please Google them yourself
Kotlin in Action
This book will start from the basic features of the language, gradually covering more advanced features, especially focusing on how to integrate koltin into existing Java engineering practice and the principles behind it. The book is divided into two parts. The first part explains how to start using kotlin's existing libraries and APIs, including basic syntax, extended functions and extended attributes, data classes and associated objects, lambda expressions, and data type system (focusing on the concepts of nullability and set). The second part shows you how to use kotlin to build your own API, as well as some deep-seated features -- Convention and delegation properties, high-order functions, generics, annotations and reflection, and domain specific language construction. This book is suitable for the majority of mobile developers and beginners, especially the frontier explorers following the mainstream trend.