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)

Writing the contents to a file

In this recipe, we are going to learn how to easily create a new File and write text to it. We are going to use the File.writeText() extension function offered by the standard library. Then, we are going to verify whether the file was successfully created and whether it contains the proper contents by printing it to the console.

How to do it...

  1. Import the File.separator constant and assign an alias to it:
import java.io.File.separator as SEPARATOR
  1. Specify the path to the new file we are going to create:
val fileName = "src${SEPARATOR}main${SEPARATOR}resources${SEPARATOR}temp_file"
  1. Instantiate the file using the specified file path:
val fileName = "src${SEPARATOR}main${SEPARATOR...