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 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.
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 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
- Named parameters
- Parameter default values
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.
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.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.
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
set() functions for
var properties. Customized versions of
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.
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
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.
Think of destructuring as a simple way of breaking up an object into its constituent parts. A destructuring declaration creates multiple variables at once.