Book Image

Programming Kotlin

Book Image

Programming Kotlin

Overview of this book

Quickly learn the fundamentals of the Kotlin language and see it in action on the web. Easy to follow and covering the full set of programming features, this book will get you fluent in Kotlin for Android.
Table of Contents (20 chapters)
Programming Kotlin
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface

Destructed declarations


If you create an instance of BlogEntry and then get the autocompletion dialog and navigate through the available methods, you will notice nine methods; these methods start with a series of components: component1(), component2(),... component9(). Each of these methods correspond to each of the fields defined by the type. Their return type will therefore match their respective field type. Here is the snippet for component6(), corresponding to the url field:

public final java.net.URI component6();
Code:
  0: aload_0
1: getfield      #51                 // Field url:Ljava/net/URI;
4: areturn

The Scala developer reading this will most likely think of the Product class and pattern matching. Kotlin is not as powerful when it comes to pattern matching, but still gives you a flavor of it.

You might find it quite useful to break the object into a tuple of variables. Given the preceding instance of blogEntry, we can actually write the following:

    val (title, description, publishTime...