Our world is surfing on a tide of advancement that is never-ending. And this process will not end in near time. It will continue till we exhaust ourselves.

It is the year 2021 and we have developed a propensity for downloading applications for our work and simple way of life. At least, this is the case with everybody and presumably, we use applications that potentially help in our day-by-day lives and a lot more stuff. Online classes, meetings, shopping, healthcare services, Financial application solutions, and everything. Also, as Android phones are utilized by 80% of the number of people on the planet, android applications are consistently in pattern and popular. Because of this pattern, the android application development company mounts profits. But the developers face an issue about what programming stack should they choose to develop an android application. Thank god, this confusion was blown away by Kotlin.

Kotlin

Kotlin is a cross-stage, statically composed, broadly useful programming language with type deduction. Kotlin is intended to interoperate completely with Java, and the JVM rendition of Kotlin’s standard library relies upon the Java Class Library, however, type surmising permits its programming structure to be more precise. Kotlin is an advanced statically composed programming language utilized by more than 60% of expert Android designers helping boost productivity, developer satisfaction, and code safety.

Kotlin Tools

Android Studio

Android Studio offers first-class support for Kotlin. It even has built-in tools and options to help you through the process of converting Java-based code to Kotlin. The Show Kotlin Bytecode tool lets you see the equivalent Java-based code as you learn Kotlin.

Android KTX

Android KTX creates Android application development with Kotlin more precise, and concise, pleasant, and idiomatic by attaching Kotlin language features.

Android KTX is a bunch of Kotlin extensions that are included with Android Jetpack and other Android libraries. KTX extensions provide precise, natural Kotlin to Jetpack, Android platform, and other APIs. To do so, these extensions attach several Kotlin language features, including the following:

  • Extension functions
  • Extension properties
  • Lambdas
  • Named parameters
  • Parameter default values
  • Coroutines

Kotlin-friendly SDK

Starting with Android 9 (Application Programming Interface level 28), the Android SDK includes null annotations to help avoid NullPointerExceptions. API reference documentation is also available in Kotlin.

Learning resources

Explore a curated set of resources in various formats to help you jumpstart learning Kotlin.

Features of Kotlin

Single type system

Java has two separate type systems, primitive types and reference types (a.k.a., objects). There are many reasons why Java includes two separate types of systems. Actually, that’s not true. As outlined in my article A case for keeping primitives in Java, there is really only one reason for primitive types–performance. Similar to Scala, Kotlin has only one type system, in that there is essentially no distinction between primitive types and reference types in Kotlin. Kotlin uses primitive types when possible but will use objects if necessary.

Default versus explicit imports

Kotlin implicitly imports kotlin.*, which is barely analogous to Java importing java.lang.*, but Kotlin also imports kotlin.io.*kotlin.collections.*, and classes from various other packages. Because of this, Kotlin source files normally require fewer explicit imports than Java source files, especially for classes that use collections and/or standard I/O.

Cleaner, more compact syntax

Kotlin does not require semicolons, and it allows omitting the return type for functions. Let’s consider a few other features that help make Kotlin a cleaner, more compact alternative to Java.

Type inference

Kotlin allows you to declare a variable as var x : Int = 8, or you can use the shorter but just as clear version var x = 8. (While Java now supports var declarations, this exclusive feature did not appear until Java 10, long after the feature had appeared in Kotlin.)

Kotlin also includes val declarations for read-only variables, which are analogous to Java variables that have been declared as final, meaning the variable cannot be reassigned. 

Properties versus fields

Kotlin has properties. Properties that are declared & accessed in a manner that is way too similar to public fields in Java, but Kotlin offers default implementations of accessor/mutator functions for properties; that is, Kotlin provides get() functions for val properties and both get() and set() functions for var properties. Customized versions of get() and set() can be implemented when necessary.

Most properties in Kotlin have backing fields, but it is possible to define a computed property, which is essentially a get() function without a backing field.

String templates

Strings can contain template expressions, which are expressions that are evaluated with results inserted into the string. A template expression begins with a dollar sign ($) and consists of either a basic name or an arbitrary expression in curly braces. String templates can shorten string expressions by minimizing the need for explicit string concatenation.

No checked exceptions

Kotlin does not have checked exceptions. While they were very good, Java’s checked exceptions have been widely criticized. You can still throw and catch exceptions, but the Kotlin compiler does not force you to catch any of them.

No call to ‘new’ for constructors

In Kotlin, the keyword is not required to create a new object. To call a constructor, using the class name with parentheses. 

Extends and implements

Java programmers know that a class can extend another class and implement one or more interfaces. In Kotlin, there is no syntactic difference between these two similar concepts; Kotlin uses a colon for both. 

Destructuring

Think of destructuring as a simple way of breaking up an object into its constituent parts. A destructuring declaration creates multiple variables at once.