Book Image

Kotlin Programming Cookbook

By : Aanand Shekhar Roy, Rashi Karanpuria
Book Image

Kotlin Programming Cookbook

By: Aanand Shekhar Roy, Rashi Karanpuria

Overview of this book

The Android team has announced first-class support for Kotlin 1.1. This acts as an added boost to the language and more and more developers are now looking at Kotlin for their application development. This recipe-based book will be your guide to learning the Kotlin programming language. The recipes in this book build from simple language concepts to more complex applications of the language. After the fundamentals of the language, you will learn how to apply the object-oriented programming features of Kotlin 1.1. Programming with Lambdas will show you how to use the functional power of Kotlin. This book has recipes that will get you started with Android programming with Kotlin 1.1, providing quick solutions to common problems encountered during Android app development. You will also be taken through recipes that will teach you microservice and concurrent programming with Kotlin. Going forward, you will learn to test and secure your applications with Kotlin. Finally, this book supplies recipes that will help you migrate your Java code to Kotlin and will help ensure that it's interoperable with Java.
Table of Contents (21 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

How to copy data class with modifications


In the last recipe, we learned how to use data class and how it reduces a lot of boilerplate code. In this recipe, we will see how data class makes it easy to copy another data class, even if you have to modify the property.

A brute-force mechanism to copy a data class can be to just create a data class by duplicating all the properties, but using the copy method will make it much easier.

Getting ready

We will be using IntelliJ IDEA to write our code. You can use any IDE that is capable of executing Kotlin code.

How to do it…

We will be using the copy method, which takes in named arguments and creates a copy of the object with changed values of named arguments. Let's look at an example:

data class Student(val name:String,val roll_number:String,var age:Int)
fun main(args: Array<String>) {
    var studentA= Student("Aanand Roy", "2013001", 21)
    var olderStudentA=studentA.copy(age = 25)
    println(olderStudentA.toString())
}

//Output: Student(name...