Why should you learn Kotlin?

In 2010, JetBrains started to build Kotlin – a universal language that is concise, expressive, and interoperable with Java which can address the common problems that developers face. Later in 2012, it was open-sourced and improved based on the constant feedback from the developer’s community and was finally released in 2016. Kotlin is a powerful modern language that can be used everywhere: i.e android application, server-side development, native apps, data science as well as Javascript, and the list is still growing. 

It is gaining its popularity among developers because it allows them to write safe, concise, and pragmatic code which is interoperable with Java. Millions of applications have been successfully created using Kotlin.  

If you are interested to explore this impressive language, then congratulations you are in the right place. This article will give you a quick overview of some of the cool features in Kotlin.

Safety

A language is considered safe if we can avoid some of the common errors that developers make while coding. 

Often, we developers make a mistake of trying to refer to a variable that does not hold any value or is null. This mistake has led to a loss of billions of dollars in the past 4 decades( it is also called a billion-dollar mistake). Kotlin helps us to prevent such a simple yet deadly error with the help of its Nullability feature. Want to learn more? Check out my article Null Safety.

Concise

A programming language is concise when the intention of the code can be understood with minimal effort. Kotlin allows us to write very concise code without jeopardizing clarity. It is estimated that Kotlin reduces the lines of code big time by 40% compared to languages like Java. 

When we build an application, we tend to write a lot of boilerplate code. Kotlin compiler is very powerful and it generates some of the redundant code for us. For example, if we declare our class as a Data class for then the compiler will provide an implementation for getters, setters, and methods like equals(), hashCode(), toString(), copy(), and componentN() for each of the parameters passed in the constructor.

Statically Typed

Kotlin is a statically typed programming language, which means the type of the expression must be known at the compile time. However, Kotlin does not require you to specify the type of variables as it’s compiler can determine the type based on the context. This capability is known as Type Inference.

const val number = 10
const val multiple: Int = number * number

The Intellij IDE  supports you to see what is being inferred from the context. You can see in the example above, that the variable “multiple” is inferred as an integer because it is a result of multiplying two numbers.

Extension Function

Kotlin enables us to add new functionalities to third-party classes or libraries. Those additional functions are defined outside of a class and they are called an extension function. You can write your extension function as shown in the example below. 

fun String.getLastElement() = this[this.length - 1]

In addition to that, Kotlin also provides a lot of built-in extension functions for millions of classes written in Java.

Default Arguments

In Kotlin, we can provide default values to arguments in a function. For instance

fun performCalculation(a: Int = 2, b: Int = 3): Int {
    val addition = a + b
    println("The sum is $addition")
    return addition
}

Named Argument

In addition to default arguments, Kotlin allows us to use the parameter name while passing arguments to any function or constructor. 

data class User(val name: String = "", val age: Int = 0)
val user = User(age = 19, name = "Sonia")

Destructuring Declaration

Kotlin provides us a technique to unpack a class instance into separate variables. Given an object, you can create standalone variables from its class variables, with just a single line of code. This technique is called destructuring declaration.

val sonia = User("sonia", 19)
val (name, age) = sonia

String Interpolation

Kotlin allows us to have a variable or expressions inside a string. The variables or expressions are substituted by their actual value when such string is used.

val name = "Sonia"
val age = 19
println("$name is ${age + 2} years old.") // returns "Sonia is 21 years old"

Interoperability with Java

Kotlin codes are compiled to .class files just like Java. Hence, we can easily access the java library, classes, and interfaces via Kotlin and vice versa without compromising the performance of the code. IntelliJ IDEs can also effectively compile a project that has a mixture of Kotlin and Java code. 

Pragmatic

Kotlin is invented to solve a real-world problem. It’s designed to address the common issues faced by the software developer. It’s been used by JetBrains since 2011 and a lot of improvements have been done before the official release in 2016.

Kotlin for server-side

Kotlin can be used to write backend services using various frameworks like Ktor, Spring Boot, http4K, and Quarkus. Also, because of Kotlin’s interoperability with Java, it works very well with the existing Java-based libraries and frameworks like Spring boot, Assertj, Jackson, etc to build powerful and scalable web applications. To learn more about Kotlin for the server-side, please check out the following link. 

Kotlin for Android

Kotlin’s language features, combined with a special compiler plug-in supporting the Android framework, turn android development into a much pleasurable and productive experience. Google has recommended using Kotlin for android development and there are millions of apps that are already using it. Android documentation includes the coding snippet written in Kotlin, to make it easier for the developers to get started with.

Kotlin for Native

Kotlin can be compiled to a native binary that can run in any platform where the virtual machine is not available or possible. This enables us to use the Kotlin code with native code, static or dynamic C libraries, Swift/Objective-C frameworks, graphical engines, etc. To learn more about Kotlin Native, please check out the following link. 

Kotlin for Data Science

Kotlin can integrate very well with the most popular IDE like Notebook for data analysis. Kotlin also has its own Kernel that enables us to write and run Kotlin code in the Jupyter notebook. There are a bunch of libraries like kmath,  kotlin-statistics, krangl, lets-plot, kravis, etc that makes data analysis with Kotlin a great experience. To learn more about Kotlin for Data Science, please check out the following link.

So, isn’t Kotlin a very cool programming language? We can do a bunch of different things if we know it. If you want to learn more in detail then please feel free to check out the tutorial which will help you get started with Kotlin.