Kotlin Basics

Learn the basics of Android’s recommended programming language, Kotlin.

Kotlin’s main features

JetBrains, the company behind popular IDEs like IntelliJ IDEA, developed and released Kotlin in 2016. Kotlin is Google’s official language for Android development since 2017. Kotlin is a statically typedIn statically typed languages such as Kotlin, Java, and C++, we explicitly mention the variable types, and the compiler knows the types of variables at compile time. However, Python is a dynamically typed language. programming language that’s more concise, safe, and interoperable than Java, the traditional language for Android development.

Kotlin is a powerful and versatile language that offers many benefits for Android development. Kotlin’s great features for Android development include:

  • Concise syntax: Kotlin’s syntax is more concise than Java, with features like automatic type inference of expressions and string interpolation (i.e., substitution of values of variables into placeholders in a string). Kotlin’s concise syntax and reduced boilerplate code can help us write code faster and with fewer errors.

  • Null safety: Kotlin’s type system includes nullability annotations and the ? operator, which helps prevent null pointer exceptions. This can help reduce the number of bugs and crashes in Android apps.

  • Interoperability with Java: Kotlin works seamlessly with Java code, which means that we can use Kotlin and Java together in the same project. This makes it easy to integrate Kotlin into existing Android apps or libraries.

  • Functional programming support: Kotlin includes features like lambdas and higher-order functions that make it easy to write functional-style code and can help make code more concise and expressive. This can also make it easier to write concurrent or asynchronous code.

  • Better code readability: Kotlin’s syntax is more readable and intuitive than Java, making it easier for us to understand and modify existing code. Kotlin also includes features like named parametersSupport for function calls with each argument associated with a given parameter. that help make code more expressive and easier to read.

Basic syntax

Now we dive into basic Kotlin syntax and learn how to write simple programs in Kotlin.


In Kotlin, we can declare variables using either the val or var keywords. The val keyword declares read-only (immutable) variables, which means that once we assign a value to the variable, it can’t be changed. The var keyword declares variables that we can reassign values to (mutable). Here’s an example of declaring variables in Kotlin:

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