Book Image

Kotlin Standard Library Cookbook

By : Samuel Urbanowicz
Book Image

Kotlin Standard Library Cookbook

By: Samuel Urbanowicz

Overview of this book

For developers who prefer a more simplistic approach to coding, Kotlin has emerged as a valuable solution for effective software development. The Kotlin standard library provides vital tools that make day-to-day Kotlin programming easier. This library features core attributes of the language, such as algorithmic problems, design patterns, data processing, and working with files and data streams. With a recipe-based approach, this book features coding solutions that you can readily execute. Through the book, you’ll encounter a variety of interesting topics related to data processing, I/O operations, and collections transformation. You’ll get started by exploring the most effective design patterns in Kotlin and understand how coroutines add new features to JavaScript. As you progress, you'll learn how to implement clean, reusable functions and scalable interfaces containing default implementations. Toward the concluding chapters, you’ll discover recipes on functional programming concepts, such as lambdas, monads, functors, and Kotlin scoping functions, which will help you tackle a range of real-life coding problems. By the end of this book, you'll be equipped with the expertise you need to address a range of challenges that Kotlin developers face by implementing easy-to-follow solutions.
Table of Contents (11 chapters)

Working effectively with lambda expressions

In this recipe, we are going to explore the concept of lambdas and closures. We are going to write part of an Android application code responsible for handling button-click actions.

Getting ready

In order to implement this recipe's code, you need to create a new Android application project using Android Studio IDE.

Let's assume we have the following class, which is a sort of a controller of the application view layer:

class RegistrationScreen : Activity() {
private val submitButton: Button by lazy { findViewById(R.id.submit_button) }

override fun onCreate(savedInstanceState: Bundle?) {

        // hook function called once the screen is displayed
}
}

It contains...