Java vs. Kotlin: Which is the Better Option for Android App Development?

Major Difference Between Java and Kotlin Programming Languages

To easily understand the difference between the two, you first need to know that Kotlin is a statically typed language for programming but Java is programming language that is object oriented.

Kotlin is a newer language than Java and through it you can easily incorporate modern features in your applications. Kotlin is best suited if you planning to develop applications that will run on the server side. One more USP of Kotlin is that its code can be written in an easy, clear and concise format.

The JVM or Java Virtual Machine is necessary to execute or run any applications that are written in Java language.

What is Java?

Java was first used back in 1995 and its primary development tool place at Sun Microsystems. It’s an object oriented programming language and can be credited with popularizing this method of programming where objects were deployed to represent data and other elements. Its emergence edged out procedural programming majorly.

It’s not advisable to run Java programs on the browser, because then you will need to deploy Java Applets too. These applets are integrated as plugins which can make application management difficult. Back end development is a more suitable development job that can be done through Java.

OpenJDK is the primary implementation of the Java language till data, and despite all else, Java is still the most preferable choice by developers worldwide when they need to develop applications for Android. This is because of the environmental congruity powered by Java as Android itself is developed and written in it.

What is Kotlin?

IDE Jet Brains came up with this new programming language called Kotlin to handle major features that couldn’t be handled through Java. While Kotlin has been around since at least 2011, its official release came in the year 2016. Unlike Java, Kotlin is an open source language, giving it major security and development advantages over Java.

Even if you want to use existing Java stacks with Kotlin, the language will allow you to do that easily. A plugin installation is all that’s needed to make the shift from Java to Kotlin. Kotlin is a statically typed programming language and Google I/O announced that Kotlin has now been recognized by it as one of the officially supported languages for application development in the Android domain.

Java Has Multiple Issues That Have Now Been Solved With Kotlin:

  • The type system majorly authorizes any null references present
  • Raw types of any kind are not present in it
  • Arrays didn’t have invariance in Java but they have it in Kotlin
  • Java’s SAM-conversions didn’t have function types but Kotlin has them
  • Wildcards are not required to deploy or utilize site variance
  • Java did have checked exceptions but Kotlin eliminates this need

Features Exclusive To Java That Are Not Present In Kotlin

  • Members are static
  • Multiple types of wildcard
  • Fields are primarily non private
  • Checked exceptions
  • Availability of non-classes primitive types
  • Ternary operator

Features Exclusive To Kotlin That Are Not Present In Java

  • Availability of Null-safety
  • Presence of Smart casts
  • Presence of String templates
  • Multiple types of Properties
  • Availability of Primary constructors
  • Extension functions
  • Delegation available of the first class
  • Variable and property types have different kinds of type inference
  • Singletons
  • Projections of type
  • Variance in declaration sites
  • Multiple types of range expressions are available
  • Operator overloading
  • Companion objects
  • Different types of data classes are available
  • Read only and mutable set of collections, both have different interfaces earmarked for them
  • Coroutines

Java was the past of Android and Kotlin is the current and probably the future of Android development languages.

Kotlin has now become the preferred language that Android app developers should use, as announced by Google in it’s latest update about Android programming languages.

In a blog about this announcement, Google mentioned that “Android development will become increasingly Kotlin-first,” It further went to say that “Many new Jetpack APIs and features will be offered first in Kotlin. If you’re starting a new project, you should write it in Kotlin; code written in Kotlin often mean much less code for you-less code to type, test, and maintain.”

At I/O 2017, three years ago, Google relayed the announcement that its Android Studio IDE will now have support for Kotlin. Before this, Java had been the primary Android app development language for developers out there, so this announcement did come off as a bit off a surprise, but this was definitely one of the key highlights of I/O 2017.

Since then, in the last three years, Kotlin’s popularity as a highly preferred Android development language has steadily gained steam. Now, Kotlin is being used in more than 50% of the apps being developed and rolled out on the Google Play Store by Android developers. This news was shared by Google itself.

Even some credibly industry surveys have given credence to this fact. Stack Overflow Developer Survey came out with the results that Kotlin is now the fourth most preferred programming language out there.

Before all this occurred, Java was the official language for development on the Android platform as relayed by Google. This explains the fact as to why a majority of Android is written in Java. Till then, all the APIs on Android could only be utilized if you called them via Java.

You could use the Android Native Development Kit (NDK) to develop apps in C and C++ even then, but Google definitely didn’t prefer this.

Google said that native code usage in developing for Android increased the app’s complexity while not providing much on the performance front, underlining the reason why C and C++ were not promoted.

The Kotlin programming language has seen an exponential rise in the development world, with developers recognizing the benefits of its implementation. As of 2019, The Kotlin mobile app development community continues to expand. A few years ago, Google’s acknowledgment for Kotlin made it the second official language for Android app development, topped only by Java.

With this announcement, Google positioned Kotlin as their preferred language for app development. For android app developers, this was a sign of a significant transition. At its core, Kotlin’s purpose is to provide developers an easier to use, less text-bulky and more intuitive development language.

Defining Kotlin and Java.

Kotlin is a statically typed programming language for Java Virtual Machine (JVM) and JavaScript. As a general-purpose programming language, it introduced new a set of new functional features to support Java interoperability. This allows a Kotlin-based code to read and interpret a code written in Java. This is because Kotlin is based on Java’s own library, with additional extensions to make it a more compact solution.

The goal of Kotlin was to increase the productivity of the development cycle. By making a language that is concise and easy to implement. This would not just save time but also cost and effort, making the coding process significantly less strenuous.

The improvement in the coding syntax with the requirement of simpler expressions reduces boilerplate code. This fulfills a long-existing wish from Android developers, making their work a lot easier. This is especially effective for mixed-language projects, enabling developers to have a lot more freedom in the process.

On the other hand, Java is an old-school classic. This programming language has a vast library of open-source tools and libraries for developers to deploy. For an extensive period of time, Java has been the leading Android app development language. Java app development has integrated itself within development teams, with everyone using it for their projects.

Java is a great language for both native. For cross-platform development, employing platforms that support it is another debate that we have answered.

In addition to that, Android is built on Java. This allows developers access to Java libraries for help.

Kotlin as a Modern Solution.

One of Kotlin’s primary objective was to attain accessibility on all platforms. A simple concept of face value, Kotlin’s mission goes a lot deeper. It aims to make sharing code between all platforms possible and accessible. Kotlin 1.3’s release was a step in the right direction with improvements to Kotlin/Native advancing the multi-platform convenience.

By no means is this improvement ideal. With Kotlin, which is a modern language, still being optimized through innovation there is a lot of room for improvement. Though the trend shows that for Developers, Kotlin is a step in the right direction.

Some of the more recent innovations have made mobile app scalability more attainable by supporting the ability to reuse code to substantially save time and effort. This allows developers to focus and spend extra time on far more challenging tasks.

The modern market trend seems to believe in Kotlin’s promise. Trends show enterprise leaders and mobile platforms switching to Kotlin for Android Applications. Some of the biggest industry names include Twitter, Airbnb, and Netflix.

Let’s take a deeper dive into the specific benefits of Kotlin to answer the question: What is the difference between Kotlin and Java:

Kotlin is Concise and Simple.

Amongst many things that Java is famous for, the conciseness of its code is not one of them. This is a real thorn in the side of developers.

Here, Kotlin gives them the best. Not only is Kotlin far more concise, but the readability it provides is also clearer.

The less text-intensive Kotlin’s text limitation comes with the ability to read and understand the coding better.

This allows developers to change, edit, or enhance a product with relative ease as opposed to Java.

This reduction of boilerplate code solves a big problem for developers, for whom checking for errors is incredibly hard. To identify and rectify bugs and mistakes takes a lot of time. With Kotlin, this becomes much easier.

To comprehend the extent to which Kotlin helps reduce coding to save time is self-explanatory through the image above. Notice how even from a mere glance at the two sides, you can notice a drastic difference.

This difference is perhaps one of Kotlin’s greatest achievements in terms of its goals. Here the ability to scan and identify bugs and make necessary changes is easier, with both the codes giving the same functional result.

One of them is just simpler, easier and more intuitive than the other.

Interoperability through Bytecode.

At its core, interoperability has been the main focus of Kotlin. Making every library accessible to Kotlin programmers to help them use existing knowledge to deliver better results.

Developers can simply write modules in Kotlin that functions seamlessly with the existing Java Code. A Kotlin compiler allows the two languages to work in unison in the same project, by emitting the Bytecode.

This is an important factor of consideration for developers who are in the process of transitioning from Java to Kotlin. In its absence, the transition would be a paramount shift.

Inherent Null Safety and automation.

Kotlin’s comes with an inbuilt Null safety feature. The NullPointerException is largely responsible for the mistakes within the app development process. In Android, a null represents a missing value, but null can easily throw all of the hard work out of the window in an application.

With Kotlin, this problem is solved through the integration of inherent null safety. This makes the need for writing extra code for workarounds redundant and unnecessary. For developers, this is perhaps the worst part of their work, which is now automated.

For laymen, you could say that Kotlin is just simply smarter than Java with problem-solving and creating process optimization.

The Business Benefits of Switching to Kotlin

Redoing large portions of a project in a new programming language is a serious decision; however, Kotlin offers two indispensable business benefits impacting the decision.

Reduced Project Timelines

For Businesses, Kotlin’s succinct nature of coding is a great asset. It saves time in development, code modification, code reviewing and bug fixes.

This allows them to reduce both the project timeline and cost, giving them a significant competitive edge.

This is important in today’s competitive market to be able to perform better than competing businesses.

Product Quality, Enhancement, and Support

For developers, app crashes are a heartache. With Java’s extensive coding, it means more than just the existence of an error.

It also means the need to spend a large amount of time to go through the code to identify the mistake. The bigger the code, the more hidden the error in the coding.

With Kotlin, this precise code allows for an easier time to fix bugs and crashes and provide long-term support.

It also allows for the application interface to be far cleaner as opposed to Java programs, due to the programmers having a greater sense of control and clarity during the development process.

Should you switch from Java to Kotlin?

In terms of pure benefits, Kotlin is definitely a better language for android app development. The Kotlin vs Java debate is fought on two fronts. First, let’s discuss the present.

Kotlin being a relatively new language does have information gaps. These gaps can often lead to a problem-solution gap for developers. While the community is growing and more information is being cultivated, in comparison to a classic like Java, it is still maturing.

This could lead to a few problems for developers who might not know how to solve certain problems using Kotlin that they could solve with Java.

The second front is the future. Kotlin is the future, with its immense benefits, lower workload and easy functionality, it is a developer’s choice of language. As the community for Kotlin grows, its popularity has skyrocketed in the industry. The increase in code lines from 2.1 to 10 million in just one year from 2016–2017 marks the rise in Kotlin’s popularity.

Here, the question becomes, is Kotlin Replacing Java? The predication of Kotlin on improving upon Java makes it an evolutionary inevitability that it will most likely replace Java in the long run. Thus, the need to prepare for the switch is necessary. Eventually, the need for this switch can become imminent and to gain a competitive edge, businesses will have to switch.

Based on this, if not an immediate switch, companies and businesses need to start preparing for one. Switching from Java to Kotlin can lead to some problems with product architecture due to class deletion and other implications.

This is why the measure needs to be carefully handled and it needs to be analyzed whether a team is ready for this switch or not. Switching in a sustainable and gradual manner might be the best way to go about this, for a complete transition over a period of time. This time can be used to assess market trends, Kotlin’s evolution and its eventual position in the industry for a better-informed decision

Originally published at on April 14, 2020.




TekRevol prides itself for being the pioneer of App Development Services in the United States. We have been in business since the launch of the first Mobile-app

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TekRevol LLC

TekRevol LLC

TekRevol prides itself for being the pioneer of App Development Services in the United States. We have been in business since the launch of the first Mobile-app

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