Kotlin 101 and beyond

All about Kotlin: 8 steps to app creation

Vikash Kumar
© Shutterstock / Andrey Suslov

Kotlin has gained the attention of many programmers lately, and for a good reason! In this article, Vikash Kumar shows you what this language has to offer and how to compares to Java. Get ready to make your first Kotlin app.

Tour the basic guidelines for using the Kotlin programming language. This article defines its merits and demerits, along with the Java issues which Kotlin solves. It also focuses on famous applications built on the platform. Finally, you also find yourself how to build your first Kotlin application using the Android studio with little to no Java.

What is Kotlin?

Kotlin is an open source programming language. Unlike Java and JavaScript, it is fairly new. It is a high-level language that strongly and statically combines functional and technical parts in the same place. Currently, Kotlin targets Java and JavaScript. Kotlin runs on a Java Virtual Machine or uses the LLVM compiler infrastructure. It is widely used in developing Android mobile applications.

Kotlin is also influenced by other programming languages such as Scala, Groovy, Gosu, etc. Its syntax is dissimilar to Java, however, internally it is dependent on the existing Java Class library to produce wonderful results. Kotlin provides interoperability, code safety, and clarity to programmers around the world.

Why prefer Kotlin over other languages?

Kotlin is 100% interoperable with Java, so while writing in Kotlin you can call Java code in it and vice versa. It has great IDE and tooling support. It also includes smart extension functions to build clean APIs.

Besides this, Kotlin has the natural advantage of being able to leverage all the language design expertise gained by Java. Hereby, we look at the benefits of Kotlin as compared to Java.

Kotlin embarks concise

Kotlin is way more concise, as it solves the same problems with fewer lines of code. This improves code maintainability and readability. Developers can write, read, and change code more effectively and efficiently. It also includes features such as type inference, smart casts, data classes, and properties to help achieve conciseness.

Safer code

It is inherently safer because it prevents common programming mistakes by design, resulting in fewer system failures and application crashes. While using Java, certain error causes are more likely to occur. Kotlin makes the developers think about potential problems with their code explicitly, thus helping them write more robust code.

Better support for functional programming

Functional programming is a development pattern that allows developers to solve many tasks more easily and consistently. It was also introduced in Java 8 version, but Kotlin has much better support for functional programming. In brief, functional concepts can be used more concisely and explicitly with proper function types. Also, performance can be improved with inlining functions which are not currently possible in Java.

Boosts every-day development tasks

Kotlin offers some handy features that facilitate every-day development tasks, something Java does not offer. These include default parameter values, object declarations, extension functions, and many more. This helps speed up development time while keeping the code base more maintainable.

Minor errors and bugs in the code

The Kotlin compiler aims to stop-first whenever possible. This efficiently facilitates searching for bugs and can even prevent them in the first place. It performs many checks, avoiding runtime errors, and reduces the cost and effort of error fixes.

SEE ALSO: Meet Everest: A slick REST API testing client written in JavaFX

Increases quality and also shrinks the base code

Migrating to Kotlin may reduce technical debt by some degree. Technical debt is defined as the dead weight developers carry due to shortcuts made in programming, often to reach a deadline. It slows down further development and reduces productivity. Using Kotlin minimizes technical debt because the code base shrinks while increasing quality at the same time. If implemented correctly, this reduces fewer lines of code for easier maintenance.

Satisfaction in work for developers

According to RebelLabs’ survey of over 2000 Java developers, they’re the most excited about using Kotlin, as well as the most satisfied with it. JAXenter also proposed Kotlin as a potential candidate for the programming language of the year in 2017 due to the satisfaction stats and its ascent in the popular TIOBE index. Google’s own survey confirmed that Kotlin catches the interest of a surprising portion of JAXenter’s readers. However, due to the increasing preference of Kotlin by developers and its feasibility of use, ado helps keep developers more satisfied and engaged on the job.

A chance to take skills to next level

Developer expertise improves while adapting to Kotlin. Java developers learn Kotlin well enough and very quickly. As they dive deep into the language, they’ll learn about good compiler and language design, asynchronous programming challenges and solutions, as well as certain language design decisions.

Renowned applications developed in Kotlin

Kotlin comes packed with many features including Interoperability with Java and Android Studio support. This was good enough for Google to validate the language’s position in the world on Android Application Development Industry. When developing Android applications, it is strongly recommended over Java. Hereby, we look at the 14 different applications that gained fruitful results using Kotlin.

  1. Pinterest moved away from Java and used Kotlin for their Android Application Development
  2. Gradle built developing android files (APK files) for both IDEA and Eclipse
  3. Evernote has integrated Kotlin in their android client
  4. Corda created interoperable blockchain networks.
  5. Coursera built an online courses application on a range of different topics.
  6. Uber made internal tooling processes such as annotation processors and Gradle plugins.
  7. Spring by Pivotal made its Java framework uses Kotlin to provide concise APIs.
  8. Atlassian and Trello did a full code conversion of the old codebase.
  9. Basecamp 3 experienced a huge difference in code quality and speed using Kotlin.
  10. Twidere for Twitter This Fell feature open source client app customizes themes, manages unlimited accounts, and filters unwanted tweets.
  11. Shadowsocks helps surf the internet safely and privately.
  12.  Simple Calendar provides an Ad free open source application.
  13.  Kickstarter helps find resources for people showcasing creativity.
  14.  Square approved Kotlin in their application to implement payment platforms.

8 quick steps to create your first Kotlin application

1. Getting Started

This guide is for programmers and assumes that you know either Java or Kotlin. The Android apps are written in Kotlin or Java using an IDE called Android Studio.

2. Install Android Studio

Android Studio is used to build Android apps. Android Studio is available for Windows, Mac, and Linux computers. The installation is similar for all platforms.

You can further learn how to download Android Studio if troubleshoot any issue.

SEE ALSO: Steep learning curve or lack of commitment? Which are the most difficult programming languages to learn and why?

3. Create your first project

  1. Open Android Studio.
  2. In the main Welcome to Android Studio dialog, click on Start a new Android Studio project.
  3. In the New Project dialog, give your application any name.
  4. Accept the default example domain.
  5. Check the box that says to include Kotlin support.


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  1. Accept the default project location and click Next.
  2. In the Target Android Devices dialog, you need to accept the defaults and click Next.
  3. Select Empty Activity. Then click Next.
  4. In the Customize  Activity dialog, you have to accept the defaults.
  5. Click Finish.

4. Explore the project layout

In the Design tab, (at the top right of the Properties panel) click the View all properties icon. If the properties are not visable, make sure the TextView is still selected in the Component Tree.


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5. Add string and color resources

In the Design tab, notice that the entire background of the screen uses the screen background color.


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6. Add views and constraints

You will need three buttons in your application and constraints as shown:



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7. Make your app attractive

This part makes your application look and feel good, as well as user-friendly. You can sneak into different settings to pull out and attract the best features of your application.


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8. Finish Look

In the end, finalize your application with attractive features, design, and display. Get ready to view your first app!



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Vikash Kumar

Vikash Kumar works for, a .net development and mobile application development company. Vikash has published his technical insights on Entrepreneur, Sap blog and many other major publications.

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