How To Write Your First Android App With Kotlin

Are you an experienced Android developer looking to get started with Kotlin? Or maybe you’re a new developer who’s been hearing a lot about this “Kotlin” thing and want to give it a try. Either way, writing your first Android app in Kotlin is easy – especially if you use Google’s recommended development environment, Android Studio.

In this article, we’ll walk you through the steps of writing your first Android app in Kotlin. We’ll start by creating a new project in Android Studio and then adding some basic Kotlin code. So let’s get started!

What is Kotlin and why should you use it for Android development

Kotlin is a statically-typed programming language that runs on the Java Virtual Machine and can also be compiled to JavaScript source code or use the LLVM compiler infrastructure. Kotlin is sponsored byJetBrains and Google.

Kotlin was created to solve some of the pain points of Java, such as null pointer exceptions and verbose syntax. Kotlin is also fully compatible with the Java programming language, so you can use any existing Java libraries in your Kotlin code.

An introduction to basic programming concepts in Kotlin

Kotlin is a very concise language, which means that a lot of functionality can be expressed in a small amount of code. The following Kotlin code defines a function that takes two Int parameters and returns their sum:

fun sum(a: Int, b: Int): Int {

return a + b

}

Kotlin also has a convenient way to define functions that don’t return a value using the Unit type:

fun printSum(a: Int, b: Int): Unit {

println(“sum of $a and $b is ${a + b}”)

}

If you don’t explicitly specify the return type of a function, Kotlin will automatically infer it for you. In the example above, the inferred return type of sum() is Int and the inferred return type of printSum() is Unit. Kotlin also has support for higher-order functions, which are functions that take other functions as parameters or return functions as results. The following code defines a function that takes a function f and an Int x as parameters and returns the result of calling f with x:

fun apply(f: (Int) -> Int, x: Int): Int {

return f(x)

}

You can call this function like this:

apply({ x -> x * x }, 4) // returns 16

Creating your first “Hello, world!” app in Kotlin

To create a new project in Android Studio, click “File” -> “New” -> “New Project.” In the “New Project” dialog, select “Empty Activity” and click “Next.” In the “Configure your new project” dialog, enter a name for your app and click “Finish.”

You should now see the “Welcome to Android Studio” screen. Click “Open an existing Android Studio project,” navigate to the directory where you saved your project, and click “OK.”

When you open your project in Android Studio, you should see a file called MainActivity.kt in the “app/src/main/java” directory. This is the Kotlin file that contains your app’s main activity. The main activity is the entry point for your app and is where you will define the bulk of your app’s functionality. To run your app, click the “Run” button in the Android Studio toolbar. You should see a dialog asking you to select an activity to run. Select your main activity and click “OK.” Your app should now be running on your device or emulator.

scala vs kotlin

There is no clear winner when comparing Scala and Kotlin. Both languages have their own strengths and weaknesses. Scala is a more traditional functional programming language, while Kotlin takes a more pragmatic approach to functional programming. Scala also has a richer type system and supports more advanced features such as type inference and pattern matching. However, Kotlin is easier to learn and has better tooling support, making it a more attractive choice for many developers.

Kotlin is statically typed, meaning that all variables must be declared with a specific type. This makes Kotlin code more verbose than Scala code. However, it also makes Kotlin code more predictable and less error-prone.