Java vs Kotlin: A Comprehensive Comparison


By NIIT Editorial

Published on 21/06/2023

Both Java and Kotlin are popular languages for creating cross-platform apps. In 1995, Sun Microsystems introduced Java, an object-oriented programming language used to build cross-platform software. It is one of the most widely used languages for creating software for the web, mobile devices, and personal computers.

Nonetheless, Kotlin is a very recent programming language, having just been published in 2011. This language shares Java's object-oriented architecture and can even run on the same platform. Kotlin's syntax is developer-friendly, and the language itself is strong; it has also gained popularity in recent years since it is intended to be more succinct, safer, and simpler to use than Java.

The goal of this comparison between Java and Kotlin is to provide developers with a better understanding of the advantages and disadvantages of each language so that they may choose the best option for their next project. Developers may learn more about the features, syntax, and performance characteristics of each language and make an informed decision about which is ideal for their projects by comparing them. Developers may benefit from learning both Java and Kotlin, or switching between the two languages with an awareness of their parallels and distinctions.
 

Table of Contents:

  • Syntax
  • Object-Oriented Programming Features 
  • Tooling and IDE Support 
  • Performance 
  • Community and Library Support 
  • Adoption 
  • Conclusion
     

 

Syntax
 

1. Comparison of Basic Syntax

 

  • Variable Declaration: In contrast to Java, where variables must have their types stated explicitly, Kotlin permits type inference, which implies that a variable's type may be deduced by the compiler from its initial value.

 

  • Example in Java:

             arduino

             Copy code

             int num = 5;

  • Example in Kotlin

             java

             Copy code

             val num = 5

  • Control Flow Statements: Control flow phrases like if-else, for-while, and switch-case are almost identical in Java and Kotlin. Yet, the control flow statements in Kotlin are shorter and more syntax-friendly.

 

  • Example in Java:

             csharp

             Copy code

             if (num > 5) {

             System.out.println("Number is greater than 5");

             } else {

             System.out.println("Number is less than or equal to 5");

             }

  • Example in Kotlin:

              go

              Copy code

              if (num > 5) {

              println("Number is greater than 5")

              } else {

              println("Number is less than or equal to 5")

              }

  • Functions: Kotlin's function syntax is comparable to Java's, except it's shorter and supports things like named arguments and default values for parameters.

 

  • Example in Java:

             arduino

             Copy code

             public int sum(int a, int b) {

             return a + b;

             }

  • Example in Kotlin:

             kotlin

             Copy code

             fun sum(a: Int, b: Int) = a + b


 

2. Advanced Syntax Comparison

 

  • Type Inference: Kotlin, unlike Java, does not need explicit type declarations, as was previously noted. This suggests that Kotlin code may be shorter and easier to understand than Java code.

 

  • Example in Java:

             arduino

             To use this, just replicate the following code: ListString> names = new    

             ArrayListString>();

  • Example in Kotlin:

             arduino

             Use val names = arrayListOfString> in your own code ()

  • Nullability: Null pointer exceptions are prevalent in Java code and may be avoided using Kotlin's built-in null safety mechanism. Every variable in Kotlin is assumed to be non-null, thus nullable variables need specific syntax.

 

  • Example in Java:

             java

             Copy code

             String name = null;

  • Example in Kotlin:

             javascript

             Copy code

             val name: String? = null

  • Lambdas and Higher Order Functions: Kotlin's built-in support for lambdas and higher-order functions allows for more succinct and expressive programming. This is in contrast to Java, which has a higher minimum line need for similar functionality.

 

  • Example in Java:

             mathematica

             Copy code

             List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);

             List<Integer> evenNumbers = new ArrayList<Integer> ();

             for (Integer number : numbers) {

              if (number % 2 == 0) {

              evenNumbers.add(number);

              }

              }

  • Example in Kotlin:

             java

             Copy code

             val numbers = listOf(1, 2, 3, 4, 5)

             val evenNumbers = numbers.filter { it % 2 == 0 }
 


 

Object-Oriented Programming Features
 

1. Classes and Inheritance

 

  • Syntax Comparison: Kotlin, like Java, has support for classes and inheritance, but its syntax is shorter and more versatile.

 

  • Example in Java:

             arduino

             Copy code

             public class Vehicle {

                private String make;

                private String model;

              public Vehicle(String make, String model) {

                this.make = make;

                this.model = model;

                }


 

                 public String getMake() {

                 return make;

                 }

                 public String getModel() {

                 return model;

                 }

                 }

                 public class Car extends Vehicle {

                 private int numDoors;

                 public Car(String make, String model, int numDoors) {

                 super(make, model);

                 this.numDoors = numDoors;

                 }

                 public int getNumDoors() {

                 return numDoors;

                 }

                 }

  • Example in Kotlin:

                kotlin

                Copy code

                open class Vehicle(val make: String, val model: String)

                class Car(make: String, model: String, val numDoors: Int) : Vehicle(make, model)

  • Functionalities Offered: Standard OOP concepts like encapsulation, inheritance, and polymorphism are available in both Java and Kotlin. Kotlin, however, provides further features like data classes and sealed classes.

 

2. Interfaces

 

  • Syntax Comparison: Although both Java and Kotlin provide interfaces, Kotlin's interface syntax is shorter and more versatile.
  • Example in Java:

              csharp

              Copy code

              public interface Shape {

                  double getArea();

               }

              public class Circle implements Shape {

              private double radius;

              public Circle(double radius) {

                 this.radius = radius;

              }

              public double getArea() {

              return Math.PI * radius * radius;

              }

              }

  • Example in Kotlin:

             kotlin

             Copy code

             interface Shape {

             fun getArea(): Double

             }

            class Circle(val radius: Double) : Shape {

            override fun getArea() = Math.PI * radius * radius

            }

  • Functionalities Offered: Abstraction and polymorphism are supported by the interfaces of both Java and Kotlin. Kotlin's interfaces also provide default implementations, which paves the way for the development of convenience methods.


 

3. Extension Functions

  • Syntax Comparison: Although Java does not support the concept of extension functions, Kotlin does, allowing for classes to have their functionality extended without the need for a subclass.

 

  • Example in Kotlin:

             kotlin

             Copy code

             fun String.removeSpaces(): String {

             return this.replace(" ", "")

             }

             val str = "Hello, World!"

             val newStr = str.removeSpaces() // "Hello,World!"

  • Functionalities Offered: With Kotlin's extension methods, developers may easily add new functionality to existing classes without touching the underlying code. This has the potential to simplify and organise the code.


 

Tooling and IDE Support 


1. Comparison of Integrated Development Environments

Several different IDEs, including Eclipse, IntelliJ IDEA, and NetBeans, support development in both Java and Kotlin. However, IntelliJ IDEA is the most popular integrated development environment (IDE) for Kotlin development due to its robust support for both Java and Kotlin.

 

2. Comparison of Build Tools

 

  • Gradle: The popular build tool Gradle may be used with either Java or Kotlin. It offers a sophisticated and versatile approach to dependency management and project construction via the use of a domain-specific language (DSL) based on Groovy to design build scripts.

 

  • Example of a Gradle build script for Kotlin:

              scss

              Copy code

              plugins {

              kotlin("jvm") version "1.5.10"

              }

              repositories {

              mavenCentral()

              }

              dependencies {

              implementation(kotlin("stdlib"))

              }

  • Maven: Maven, a well-known Java build tool, is also compatible with Kotlin. It facilitates dependency management and project construction via the use of an XML-based configuration file to create build scripts.

 

  • Example of a Maven build script for Kotlin:

             php

             Copy code

             <project>

                 <modelVersion>4.0.0</modelVersion>

             <groupId>com.example</groupId>

             <artifactId>my-kotlin-project</artifactId>

             <version>1.0.0</version>

             <properties>

             <kotlin.version>1.5.10</kotlin.version>

             </properties>

             <dependencies>

                  <dependency>

                  <groupId>

 

               org.jetbrains.kotlin</groupId>

                   <artifactId>

               kotlin-stdlib</artifactId>

                    <version>

               ${kotlin.version}</version>

                    </dependency>

                    </dependencies>

                    </project>

  • Ant: Ant is an older Java build tool that may be used in conjunction with Kotlin. It facilitates dependency management and project construction via the use of an XML-based configuration file to create build scripts.

 

  • Example of an Ant build script for Kotlin:

             php

             Copy code

             <project>

             <target name="compile">

                 <mkdir dir="build/classes"/>

                 <kotlinc srcdir="src" destdir="build/classes"/>

             </target>

             <target name="jar" depends="compile">

              <mkdir dir="build/jar"/>

              <jar destfile="build/jar/my-kotlin-project.jar" basedir="build/classes"/>

              </target>

              <target name="clean">

              <delete dir="build"/>

              </target>

                 </project>

 


Performance
 

1. Comparison of Runtime Performance

Both Java and Kotlin are run by the Java Virtual Machine after being compiled to bytecode (JVM). So, throughout execution, they exhibit equivalent levels of efficiency. There should be no appreciable differences in runtime performance between Kotlin and Java since it is intended to be completely compatible with Java and may utilise Java libraries and frameworks.

 

2. Comparison of Compilation Time

Due to its more complicated syntax and extra language capabilities, Kotlin's compilation time may be somewhat longer than Java's. The difference in compilation time is generally insignificant, however, and shouldn't have much of an effect on things overall.

As an added bonus, Kotlin supports incremental compilation, which instructs the compiler to recompile just the modified sections of code. Kotlin's ability to be compiled to both JavaScript and native code means it may sometimes provide substantial speed gains.

 


 

Community and Library Support

 
1. Comparison of Community Size and Activity

Java has been around for more than 25 years, and its user base is large and very engaged. Java developers may get help in a wide variety of places, from online communities and user groups to in-person gatherings and conferences. This makes it simple to get assistance with programming issues or inquiries.

Nonetheless, Kotlin is a more recent language, and its user base is smaller than Java's. Nonetheless, it has attracted a large number of users in recent years, with programmers applauding its simplicity and cutting-edge capabilities. Kotlin developers have access to a thriving online community and a wealth of useful tools because to the language's popularity.

 

2. Comparison of Available Libraries

 

There is a huge selection of libraries for Java developers to choose from, accommodating a broad variety of tasks and scenarios. It's possible to find a library for just about every programming task, from web development to machine learning. Spring, Hibernate, and Apache Commons are three of the most widely used Java libraries.

Kotlin was designed to be completely compatible with Java, thus it can utilise any Java library. Kotlin also comes with its own library system, with certain libraries tailored to the language itself. Ktor, kotlinx.coroutines, and Exposed are three of the most widely used Kotlin libraries.


 

Adoption 


1. Comparison of Industry Adoption Rates

For decades, Java has been one of the most popular programming languages worldwide. Financial services, telecommunications, and e-commerce are just some of the many large-scale applications that make heavy use of it. Java is used by several Fortune 500 firms for their important software.

On the other side, Kotlin is not as widely used as Java since it is a newer language. But, it is becoming more popular, especially among Android programmers. Kotlin's popularity has skyrocketed since 2019, when Google said it will begin formally supporting it as a first-class language for Android development.

 

2. Comparison of Open-Source Projects

Spring, Hibernate, and Apache Struts are just a few of the many well-known open-source Java projects. Several of these initiatives have been operational for decades, and throughout that time they have amassed sizable and engaged user bases.

Due to its relative youth, Kotlin supports a modest but continuously expanding set of open-source endeavours. Ktor and kotlinx.coroutines are two examples of Kotlin-only libraries; others are Java libraries that have been ported to Kotlin.

Generally, there is a significantly larger number of open-source projects written in Java, but as Kotlin gains in popularity, more and more projects written in Kotlin are being created.

 


 

Conclusion
 

Both the Java and Kotlin programming languages have their advantages and disadvantages. What follows is a brief summary of the most important ideas discussed in this contrast:

1. Syntax

Kotlin's sophisticated features, such as null safety and extension functions, contribute to its compact and expressive syntax.

2. Object-Oriented Programming Features

Classes, inheritance, interfaces, and extension methods are all available in both languages; however, Kotlin's approach is cleaner and more adaptable.

3. Tooling and IDE Support 

IntelliJ IDEA is the primary integrated development environment (IDE) for both languages and provides extensive tools and IDE support.

4. Performance

Performance at runtime is comparable between Java and Kotlin, however Kotlin compiles quicker because of its succinct syntax.

5. Community and Library Support

While Java has a bigger community and library environment, Kotlin has become more popular due to its compatibility with Java and its specific Kotlin libraries.

Joining a Java developer course is highly recommended if you want to learn Java or improve your existing understanding of the language.

 



whatsapp
Top