What is Kotlin?

Kotlin is a statically typed, modern programming language developed by JetBrains. It runs on the Java Virtual Machine (JVM) and is fully interoperable with Java, which makes it an excellent choice for Android development, web development, and even backend services. First introduced in 2011, Kotlin was officially released in 2016 and has since gained significant popularity, especially in the Android development community, where it has been endorsed by Google as the preferred language for building Android applications.

Kotlin is designed to be concise, expressive, and safe. It reduces boilerplate code compared to Java and provides many modern features such as null safety, data classes, and smart casting, which enhances developer productivity and the overall quality of code. Moreover, Kotlin can be compiled to both JVM bytecode and JavaScript, enabling the creation of applications across multiple platforms, from Android to web and server-side development.

Key features of Kotlin include:

• Null Safety: Kotlin’s type system distinguishes nullable and non-nullable types, which helps eliminate null pointer exceptions (NPE), a common source of runtime errors in many applications.
• Concise Syntax: Kotlin has a more concise syntax compared to Java, which reduces the amount of boilerplate code developers need to write.
• Interoperability with Java: Kotlin is fully interoperable with Java, meaning developers can call Kotlin code from Java and vice versa, facilitating easy integration into existing Java projects.
• Functional Programming Features: Kotlin supports functional programming paradigms, including higher-order functions, immutability, and lambdas.

What are the Major Use Cases of Kotlin?

Kotlin is a versatile programming language that has found widespread use across different domains. Here are some of the major use cases for Kotlin:

1. Android Development
   Kotlin has become the preferred language for Android development. Google’s endorsement of Kotlin as a first-class language for Android applications in 2017 has significantly accelerated its adoption. Kotlin’s concise syntax, combined with features like null safety and data classes, makes it ideal for developing Android applications that are both robust and maintainable.
2. Backend Development
   Kotlin can be used for server-side development, thanks to its ability to run on the JVM. Many companies use Kotlin for building web applications and APIs. Kotlin’s compatibility with frameworks like Spring Boot and Ktor makes it a powerful tool for building backend services.
3. Web Development
   Kotlin can also be compiled to JavaScript, making it suitable for developing client-side applications. With the help of Kotlin/JS, developers can write Kotlin code for both frontend and backend applications, leading to greater consistency across the entire project.
4. Cross-Platform Development
   Kotlin Multiplatform allows developers to share code across platforms such as Android, iOS, and web applications. By writing common code in Kotlin, developers can reduce the duplication of effort and create cross-platform apps with ease. This is particularly useful in mobile development, where both iOS and Android applications can share significant portions of code.
5. Data Science and Machine Learning
   Although not as common as Python in the data science domain, Kotlin is gaining traction for use in data science, especially with libraries like KotlinDL (deep learning) and kotlinx.coroutines (asynchronous programming). Kotlin can be used for building efficient data pipelines and performing tasks such as data analysis and visualization.

How Kotlin Works Along with Architecture

Kotlin works in the JVM ecosystem, meaning it runs on the Java Virtual Machine. Its interoperability with Java allows Kotlin to be seamlessly integrated into Java-based projects. Kotlin code is compiled into Java bytecode, which can be executed by the JVM, making it compatible with existing Java libraries and frameworks. Here’s a breakdown of Kotlin’s architecture and how it fits into different ecosystems:

1. JVM Backend
   Kotlin’s primary platform is the JVM, where it compiles to bytecode that runs on the Java Virtual Machine. This means Kotlin can leverage the entire ecosystem of Java libraries and frameworks. It works well with established frameworks like Spring, Hibernate, and Apache Kafka.
2. Kotlin/Native
   Kotlin/Native is an experimental technology that compiles Kotlin code to native machine code. This enables Kotlin applications to run without the need for a JVM, making it suitable for use in environments like iOS and embedded systems. Kotlin/Native allows Kotlin to be used for cross-platform development, including Android, iOS, and desktop applications.
3. Kotlin/JS
   Kotlin/JS compiles Kotlin code into JavaScript, enabling the development of web applications. This allows Kotlin developers to write client-side code in Kotlin rather than JavaScript, making Kotlin a viable option for frontend development as well.
4. Kotlin Multiplatform
   Kotlin Multiplatform allows developers to share code between different platforms such as Android, iOS, and JavaScript. Kotlin code can be written once and shared across multiple platforms, enabling the development of cross-platform applications with fewer code duplication issues. This is especially helpful for teams who want to build both Android and iOS apps simultaneously, while still having a single codebase for business logic.

What are the Basic Workflow of Kotlin?

Kotlin follows a relatively straightforward development workflow, making it easy to get started and scale your application. Here’s an overview of the typical Kotlin development workflow:

1. Setup the Kotlin Environment
   To begin writing Kotlin code, you need to set up the Kotlin development environment. The easiest way to do this is by installing IntelliJ IDEA, the official integrated development environment (IDE) for Kotlin, which is developed by JetBrains. Alternatively, you can also use Android Studio, which provides full support for Kotlin-based Android development.
2. Create a Kotlin Project
   After setting up the environment, you can start by creating a Kotlin project. If you’re building a Kotlin project for Android, you’ll start by creating an Android project in Android Studio. For other applications, you can create a Kotlin project directly in IntelliJ IDEA.
3. Write Kotlin Code
   Kotlin applications are written using a combination of functions, classes, and objects. The primary building blocks of Kotlin include:
   • Classes and Objects: Kotlin allows you to define classes and objects with a much simpler syntax than Java, reducing boilerplate code.
   • Functions: Functions are first-class citizens in Kotlin. They can be defined inside classes or standalone.
   • Extension Functions: One of Kotlin’s unique features is extension functions, which allow developers to extend existing classes without modifying their source code.
4. Compile and Run
   Once you’ve written your Kotlin code, you can compile it into JVM bytecode (or native code if using Kotlin/Native) using the IDE’s built-in tools. When you run your Kotlin code, it executes in the same environment as Java-based applications.
5. Unit Testing and Debugging
   Like Java, Kotlin provides support for unit testing with frameworks like JUnit. Testing is an important part of the development process, and Kotlin makes it easy to write tests with features such as null safety and concise syntax. You can debug your Kotlin applications using the built-in debugging tools available in IntelliJ IDEA or Android Studio.
6. Deployment
   After completing your development and testing process, the final step is to deploy your Kotlin application. For Android apps, this means building APK or AAB files for distribution on Google Play Store. For backend applications, you can deploy Kotlin code to servers, such as AWS or Google Cloud.

Step-by-Step Getting Started Guide for Kotlin

Here’s a simple guide to getting started with Kotlin:

Step 1: Install IntelliJ IDEA

• Download and install IntelliJ IDEA from https://www.jetbrains.com/idea.
• Install the Kotlin plugin if it’s not already included (IntelliJ IDEA comes with Kotlin support by default).

Step 2: Create a Kotlin Project

• Open IntelliJ IDEA and click on Create New Project.
• Select Kotlin from the available project types and choose whether you want a JVM or Kotlin/Native project.
• Set up your project and give it a name.

Step 3: Write Kotlin Code

• Once the project is set up, create a new Kotlin file (with a .kt extension).
• Write a basic “Hello, World!” program: fun main() { println("Hello, Kotlin!") }

Step 4: Run the Code

• To run your program, click the Run button in the IDE. Your output will appear in the console window.

Step 5: Explore Kotlin Features

• Now that you have a working setup, explore more advanced features of Kotlin such as null safety, extension functions, and data classes. Start building more complex applications or explore Kotlin’s ecosystem for libraries and frameworks suited to your needs.

JavaScript is the most popular programming language among developers followed by Python and then Java, according to analyst firm SlashData’s latest survey of developers. However, in terms of adding new developers within the last one year Python leads with 2.2 million developers. Python can be classed as the fastest-growing programming language in 2020.

The company’s State of the Developer Nation Q3 2020 survey includes responses from more than 17,000 developers in 159 countries, covering the most popular programming languages, developer attitudes to open-source software, adoption of DevOps practices, and usage of popular cloud technologies, such as containers and orchestration tools like Kubernetes.

According to SlashData, JavaScript, which includes CoffeeScript and Microsoft’s TypeScript in the survey, is by far the most popular language, with 12.4 million developers reportedly using it worldwide.

It estimates five million developers have joined the JavaScript community since 2017, consolidating its position as the world’s most popular programming language.

“Even in software sectors where JavaScript is least popular, like data science or AR/VR, over a fifth of developers use it in their projects,” SlashData notes.

Despite weaknesses in web, mobile and desktop app development, Python has gained 2.2 million net new developers over the past year thanks to machine learning, data science and IoT app – or anything without a user interface.

Peter Wang, CEO of Anaconda, the maker of the Anaconda Python distribution for data science, told ZDNet in a recent interview it was “kind of a miracle that Python is even on the radar, much less ranked in the top three languages”, given its low adoption for mobile and application development.

“On the web, the frontend is always JavaScript or a derivative. And on mobile, Python is barely used at all,” he noted.

Nonetheless, Python’s developer population now stands at an estimated nine million users – or roughly 800,000 more than the estimated 8.2 million Java developers.

Python’s popularity overtook Java at the beginning of 2020, according to SlashData. This observation is consistent with several programming language popularity rankings.

Developer analyst RedMonk’s observed the switch in its June 2020 ranking, while Java hit an “all-time low” in Tiobe’s October 2020 popularity rankings and looks set to be overtaken by Python for second place. JavaScript and Python were also more popular than Java in Stack Overflow’s 2020 developer survey.

But Oracle argues 25-year-old Java is still hugely popular, used by over 69% of full-time developers worldwide with 51 billion active Java Virtual Machines (JVMs) deployed globally. And SlashData notes that the Java community gained 1.6 million developers since mid-2017, despite not growing in the past six months.

Languages with developers numbering between six million and 6.3 million include C and C++, PHP, and C#. In the next group of languages with between 2.3 million and 2.8 million developers are Google-endorsed Android app-development language Kotlin and Apple’s Swift. Swift overtook Kotlin in early 2020, according to SlashData.

According to SlashData, 60% of backend developers use containers, making it the most popular cloud technology, ahead of the 45% using database-as-a-service from the likes of AWS, Oracle, IBM, Google, and MongoDB.

Around 57% of backend developers who are using a containerized application orchestration tool choose Kubernetes.

Interestingly for DevOps adoption, SlashData found that 35% of developers don’t consider themselves to be engaged in the area, yet 40% of respondents say they practice continuous integration (CI) and 37% say they use continuous delivery or deployment (CD) – both being fundamental aspects of DevOps.

However, SlashData reckons the “full automation of the software release process – and therefore true commitment to the DevOps culture – is far from a reality”.

“While more than half (52%) of developers use CI or CD to streamline parts of their workflow, only 25% use both practices to automate all steps between integrating code changes into a central repository through to production deployment,” it notes. “As it turns out, developers are still skeptical about fully automated CI/CD pipelines. This is evident by the fact that nearly 40% of them manually give the green light for code deployments to be promoted to production.”