Kotlin Programming Language for Android App Development

Google I/O conference 2017 announces Android app development support for Kotlin language. It opens an innovative platform for those who want to design & create their Android applications. Kotlin Language is a powerful language offering a lot of specific features as well as new opportunities for Android developers.

JetBrains releases the Kotlin statically typed programming language for android app development.  It is entirely interoperable with Java frameworks having no limitations. Kotlin programming language has been used by millions of Android developers via plugin & using some favorite apps from play store like Basecamp.

Kotlin Language is an open source pragmatic programming language offering functional programming as well as object-oriented features for Java virtual machine and Android App Development. It mainly focuses on interoperability, safety, clarity, the curve as well as tooling support.

Getting Started with Kotlin Language Project:

Follow these important & easy steps to get started with Kotlin Programming Language.

To create Kotlin language project, the requirements are:

• Android 3.0+
• Android SDK

Let’s See the Most Effective and Easy Way to use Kotlin Code.

Firstly, we create a new project by android studio 3.o+ which will automatically show Kotlin support as checked, If not marked as checked then mark it.

Secondly, we define an activity & mark it tested for backward compatibility to run on older Android devices.

you have successfully created a new project in kotlin.

Top 9 Innovative Features by Kotlin Programming for Android Development

• It is one of the best programming languages for developing Android applications which bring all features of a modern programming to the Android app development platform.
• Kotlin programming language is fully capable of using all existing java frameworks as well as libraries. We can also work on advanced frameworks that rely on annotation processing too.
• The most significant support by Kotlin Programming language is that it can easily integrate with Maven, Gradle as well as other build systems.
• Kotlin Programming Language offers full compatibility with JDK 6 ensuring Kotlin applications can easily run on older as well as new Android devices.
• A Kotlin & Java application both are designed with similar bytecode structure to makes Kotlin application runs as fast as an equivalent to Java Apps.
• It is fully inter-operable with Java programming which allows using all Android libraries in a Kotlin application.
• Kotlin Language has small runtime library for developing android applications. We can minimize this runtime library by using ProGuard which is the most traditional bytecode optimizer for Java programming.
• Kotlin programming is an object-oriented language with functional programming style runs on JVM where android developer focuses on functional programming as well as its functional Web endpoints & bean registration.

Kotlin Programming Basic Functions & Syntax Definitions

Class Definition Kotlin:To create the new instance of classes in Kotlin, we declare the keyword class such as shown in the given an example:

class Invoice

{

}

Kotlin Constructors:A Kotlin class can have a primary constructor as well as one or more secondary constructors. Hence, we define the primary constructor in the class header which includes the class name.

class Person constructor(firstName: String)
{

}

Inheritance in Kotlin Language:In Kotlin language, all classes have a common superclass ” Any .” A default superclass with no supertypes declared such as:

class Example // Implicitly inherits from Any

“Any” superclass is not a part of java.lang.Object; This super keyword has equals(), hashCode() as well as toString() functions. To declare an explicit supertype, we place the variable type after a colon in the class header such as:

open class Base(p: Int)

class Derived(p: Int) : Base(p)

Extending Class Definition

// In java

public class My_Calculation extends Calculation

//In Kotlin

class Your_Calculation : Calculation()

Creating Kotlin Variables:

Val: It is an immutable reference in which variable declaration using Val keyword remain unchanged once the value assigned to that variable. It is similar to the final keyword on java.

Var: It is a mutable reference in which variable declaration using var keyword is changeable in the programming code. It is similar to normal Java variable.

var language: String = “French”

val score: Int = 95

Defining Functions in Kotlin Language:We can declare functions in Kotlin programming by using the fun keyword such as:

fun showText(message : String){

Toast.makeText(this, message, Toast.LENGTH_LONG).show()

}

Abstract Classes in Kotlin Programming:We can declare a class and some of its members as abstract. The abstract class does not have the implementation of its abstract members. We can easily override non-abstract open members with an abstract one such as shown in given examples:

open class Base {

open fun f() {}

}

abstract class Derived : Base() {

override abstract fun f()

}

Kotlin POJO Data Classes:Kotlin Programming introduces a new concept of POJO classes which works as a data container. To create POJO classes, we use keyword data in the class. Kotlin POJO classes are quite different as compared to Java POJO classes such as:

Pojo class example in java:

public class Example {
    @SerializedName("User_Id")
    @Expose
    private String UserId;
    @SerializedName("User_Name")
    @Expose
    private String UserName;
    @SerializedName("User_Phone")
    @Expose
    private String UserPhone;
    public String getUserId() {
        return UserId;
    }
    public void setUserId(String userid) {
        this.UserId = userid;
    }
    public String getUserName() {
        return UserName;
    }
    public void setUserName (String username) {
        this.UserName = username;
    }
    public String get UserPhone () {
        return UserPhone;
    }
    public void set UserPhone (String userphone) {
        this. UserPhone = userphone;
    }
}

Pojo Class Example in Kotlin:

class Example {     
@SerializedName("User_Name")    
@Expose    
var User_Name: String? = null    
@SerializedName("User_Id")    
@Expose    
var User_Id: String? = null    
@SerializedName("User_Phone")    
@Expose    
var User_Phone: String? = null
}

Few Final Words

Kotlin language delivers remarkable support for Android developers & programming community. It resolves the issue related to runtime exception & source code verbosity. It offers automated java to kotlin converter using Kotlin Koans which is a useful guide for kotlin syntax.

If you find difficulty in understanding & developing Kotlin apps, you can hire dedicated app developer for your mobile application development project to enhance your project needs.

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