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Last Updated: Aug 13, 2023

Kotlin VS Java - What's the Difference?

Author Lokesh Sharma
1 upvote


Welcome, Ninja! Are you new to app development and confused about which language to choose to start your development journey? Don’t worry. We at coding ninjas are here to help you. This article will discuss two of the most popular Android app development languages, Java and Kotlin. This article on Kotlin vs Java will clear all your doubts about language selection for Android development. We will look at each aspect of these languages one by one. 

kotlin vs java

We will start by discussing the basics and overview of both languages. We will then compare the functionalities of each language and look at their pros and cons. After comparing  Kotlin vs Java from head to toe, you will realize the right language to start with.

So let us begin with the basics.

Java Introduction

Java is a powerful object-oriented programming language that is very secure. It is one of the most popular and widely used languages that provide multi-platform functionality. Java has its API and a runtime environment known as JRE. Let us tell you one amusing fact, Android itself is written in Java.

Historically, Java was coded and released by Sun Microsystem in the year 1955. Later, Oracle acquired the company. Java is also known as Oak.

Essential Facts About Java

In our article on Kotlin vs Java we will now discuss the essential facts about Java.

  1. Java is a dynamic language. It allows runtime modifications. This statement means you can modify the code structure while the program runs.
  2. The systems developed in Java are virus-free and secure.
  3. Java provides various features, such as automatic garbage collection, and supports distributed computing. 
  4. Java allows us to create static members. These members can be declared only once and are accessible to all the objects in the code.
  5. Java provides a shorter way of writing if-else statements. We can use the ternary operator (?:), which is easier to write and read.
  6. Java supports the “write once and run anywhere” concept. Most computing platforms can run codes written in Java.
  7. It provides a very efficient memory management system with the help of Java Virtual Machine (JVM). 
  8. It also provides the feature of checked exceptions. You can try and catch errors in Java.

Printing Hello World in Java

  • Java


class HelloWorldExample {  
public static void main(String[] args) { 
System.out.println("Hello, World!");  

Advantages of Java

  1. Java provides a large bundle of third-party libraries.
  2. Being one of the most popular languages, lots of documentation and guidelines are available for learning Java.
  3. You can manually try and catch errors in Java. This method makes error handling easy.
  4. It has a huge developer community. 
  5. Applications created in Java are very secure. 
  6. Java provides excellent performance while running code and has fast compilation abilities.
  7. Java allows multi-threading. It allows you to perform multiple tasks in a single program parallelly. 

Disadvantages of Java

  1. Java has large and complex syntaxes. It is difficult to learn for beginners. 
  2. Java consumes lots of system resources and requires high processing speed.
  3. It does not offer functions like delete() and free(). This lack of functionality reduces control over garbage collection.
  4. Java is not recommended for designing Android APIs.

Kotlin Introduction

Kotlin is a universal, platform-independent programming language. It combines the features of both object-oriented and functional programming languages. Kotlin is an open-source programming language that Java strongly influences and runs on the Java Virtual Machine. This language is specially designed for android development and is fully interoperable with Java. 

Historically, Kotlin started as an open-source project in 2010. JetBrains officially released it in the year 2016. 

Essential Facts About Kotlin

Now, to better compare the difference between Kotlin vs Java, let us consider facts about Kotlin: 

  1. Kotlin is interoperable with Java. This statement means we can use codes written in Java and vice versa.
  2. Kotlin supports primary and secondary constructors and provides a fast compilation of code. We can create more than one secondary constructor.
  3. It automatically creates constructors and getter-setter methods for the classes created. 
  4. Code written in Kotlin is concise. You will find significantly less extra code in Kotlin. 
  5. You can use the IDE command-line interface for writing code in Kotlin. It is a tool-friendly language and allows you to write code in almost every Java IDE.
  6. One of the key features of Kotlin is its ability to handle the NullPointerException. This exception is one of the most feared exceptions in programming and is therefore known as the “Billion dollar mistake.” Kotlin uses the safe call operator to handle this exception.

Printing Hello World in Kotlin

  • Kotlin


fun main(args : Array<String>) {  
println("Hello, World!") 

Advantages of Kotlin

  1. Kotlin is more expressive than Java and lets you write concise code. This way, it reduces the chances of errors.
  2. It provides built-in Null exception handling, which resolves significant stress for programmers.
  3. Kotlin is very easy to read and understand. It is a statically-types language.
  4. Applications made from Kotlin are pretty easy to deploy.
  5. It is interoperable with Java and allows the exchange of information between the two languages.
  6. Kotlin divides large applications into smaller layers. 
  7. As discussed above, Kotlin automatically adds constructors and other essential methods in the newly created data class. This way, we save up a lot of time while writing new code.

Disadvantages of Kotlin

  1. Kotlin is a new language less popular than Java. Its community is small. Therefore, less documentation and tutorials are available, which makes learning difficult. 
  2. The compilation and processing speed of Kotlin is lesser than that of Java.
  3. Kotlin has a high memory consumption. Its memory management is less efficient than that of Java.

Using Kotlin over Java language in Android

Developers choose Kotlin for Android development over Java because of its code's speed and readability. It also prevents common errors associated with null values, enhancing app stability. Furthermore, Kotlin attracts innovators due to its seamless integration with Java. With modern language features, enhanced Android extensions, and native support, Kotlin provides an improved developer experience. App development becomes faster and more efficient with Kotlin's modern features and tools.

Differences Between Kotlin and Java

Till now, we have learned about the basics of both languages. It is time to compare these languages to various aspects of programming. Following is a brief comparison of Kotlin vs Java.

Null Pointer ExceptionJava does not handle Null pointer exceptions. Handles Null pointer exceptions using the Safe Call operator. 
Static Members It supports Static members for a class. It doesn't support static members for a class. 
Primitive Types Primitive types are not considered as objects. It considers primitive types as objects.
Compilation Time Java provides a fast compilation of code. Slower compilation in comparison to Java. 
Checked Exceptions We use try-catch to handle exceptions in Java. No need to declare or try-catch exceptions. 
Deployment Code written in Java is hard to deploy. Deployment is easier in Kotlin. 
Semicolons Using semicolons after every statement is necessary.

It does not require using of semicolons.

Data TypeData type of the variable must be specified while declaring it. It does not require the specification of data type.
Smart Cast feature Doesn't have the smart cast feature.It supports the smart cast.
Expressions Java does not support expressions in string. Strings declared in Kotlin support expressions such as variables and methods.
Wildcards Support Wildcards. It does not support Wildcards. 
Lambda function Older versions of Java do not provide this feature. Kotlin supports Lambda function. 
Community support Java has a vast community. 

Kotlin is a relatively new language and has a smaller community than Java.

We must always know both sides of the coin. So let us now discuss the advantages and disadvantages of each language.

Frequently Asked Questions

Do I need to learn Java before learning Kotlin?

It is optional to learn Java before learning Kotlin. Kotlin is an easy-to-learn language, and you can learn it from scratch.

Can Kotlin run without JVM?

Kotlin/Native is a feature of the Kotlin programming language that lets you turn your Kotlin code into regular computer code, so it can work without using a virtual machine like JVM.

Is Java faster than Kotlin?

Kotlin is slower to compile and run than Java because it has more additional features. On the other hand, Java is more direct and has fewer extra features, so it compiles faster.


Hey Ninja! We hope you are feeling relieved after resolving your doubts. You can now choose the right language per your requirements. We will be ending our discussion on Kotlin vs Java. We sincerely hope the above discussion helped you to understand the basics and differences between the two languages.

You can refer to our blogs on java and Kotlin if you wish to learn more about Java and Kotlin. 

C++ vs Java

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