Java vs Kotlin – Which one to pick for Android App Development?

Android apps have become an integral part of our lives. From individuals to enterprises, everyone is using these applications to perform not only daily activities along with complex business transactions.

However, it is a tedious task for any app development company to pick the best programming language to develop Android applications.

Java was ruling the roost for ages, but the equation has been changed once Kotlin made its imposing entry. Due to ever-changing user demands, Android development was long in need of a fresh language, and Kotlin very much filled that gap.

If you are venturing into the Android app development, then you must face a dilemma:

Should you use Java or Kotlin?

In this blog, we will compare Java and Kotlin to assist you to make an informed decision.

What is Java?

Java is a powerful, robust, yet simple object-oriented programming language, known for its unprecedented capabilities to build Android apps, server apps, web apps, big data apps, embedded systems, and more. Java was released in 1995 by Sun Microsystems, which is now owned by Oracle, and its most components are readily available in open source.

Java is 3rd most popular programming language on GitHub, and a large share of Android apps are developed using Java only.

Java – Advantages

• Works well for both Cross-platform and Native apps.
• Easy to understand and learn.
• Offers a wide range of Libraries to add innovative features.
• Enjoys support of a massive open-source ecosystem.
• Java applications are compact and light, which offers a blazing fast experience.
• Yields a quicker build process, that allows more code in less time.
• Offers accelerated assembly with Gradle, which enables assembling of projects easily.

Read Also: – .Net vs Java – Best Technology for Software Development?

Java – Disadvantages

• It is a type-heavy language, which means you must write more code, which increases the chances of bugs.
• Due to the inherent limitations of Java, developers experience problems with Android API design.
• Java needs more memory; it manages it via garbage collection, which makes it slower than its competitors.
• Java offers a lackluster look and feel of the GUI.
• It primarily focuses on storage, whereas it lacks emphasis on data backup.

Top Application Developed Using Java

What is Kotlin?

A group of developers from JetBrains launched Kotlin. The initial intention was to make coding in Java easier and more productive. In 2018, Kotlin become an official programming language.

Kotlin runs on the JVM (Java virtual machine), which can be compiled into JavaScript code and could be executed in modern browsers. Kotlin allows the developers to build native as well as cross-platform applications through its capable IDE.

Kotlin – Advantages

• It is much faster than Java. It requires less code, hence fewer chances of bugs and errors.
• It provides clean APIs to incorporate additional features in apps.
• Kotlin is preferable for multi-platform development.
• Kotlin supports Java bytecode, frameworks, and libraries. It allows developers to transition from Java to Kotlin without any challenges.
• Kotlin allows usage of ‘Null’ in its type-system, which is missing in Java.
• It offers a compact and precise codebase, that allows stable code for apps.
• It offers Anko Library, which allows developers to incorporate innovative capabilities into applications.

Read Also:-  Top 10 Mobile Apps Written in Kotlin Language

Kotlin – Disadvantages

• The learning curve is steep. It offers highly concise syntax, that requires adequate learning upfront.
• Kotlin is slower than Java when it comes to code compilation.
• The Kotlin developer community is still evolving and learning resources are quite limited, which hinders troubleshooting efforts.
• Kotlin is still an emerging programming language, hence finding seasoned developers is a big challenge.
• Various features of Android Studio such as code compilation and auto-complete run slower in Kotlin in contrast to Java.

Top Application Developed Using Kotin

Java vs. Kotlin – Features

Features	Java	Kotlin
Checked Exceptions	Available	Not Available
Code Conciseness	Can’t be labeled as concise	Better than Java
Coroutines	Not Available	Available
Data Classes	It requires writing large boilerplate code	Only need to mention data keyword in the class definition
Extension Functions	Not Available	Available
Lambdas and Higher-Order Functions	Lambdas expressions are incorporated in Java 8, whereas the high-order functions can be implemented via Callables.	These features are in-built
Implicit Widening Conversions	Available	Not Available
Inline Functions	Not Available	Available
Native Support for Delegation	Not Available	Available
Non-Private Fields	Available	Not Available
Null Pointer Exceptions	Available	Not Available
Primitive Types	Primitive type variables are not objects	Primitive type variables are objects
Smart Casts	Not Available	Available
Static Members	Available	Not Available
Support for Constructors	It offers multiple constructors but misses out on secondary constructors. Although.	Here we can have multiple secondary constructors
Ternary Operator	Available	Not Available
Wildcard Types	Available	Not Available, but as an alternative, we can use type projects and declaration-site variance

Java vs Kotlin – Similarities 

Java and Kotlin do offer a couple of similarities : 

Collections Library:

The collection libraries of both Java and Kotlin are quite similar, the classes are very easy to convert. It makes it easy for developers to inherit the functions of libraries to incorporate additional features and functionalities in their apps.

Type System:

Both Java and Kotlin offer similar language-type systems. It ensures your developers don’t need to worry about transforming your existing code to the new language.

Java vs. Kotlin – Differences

Parameter	Java	Kotlin
Speed of coding	Although both Java and Kotlin offer almost similar speeds of coding, Java offers more coding processes than Kotlin. It allows developers to spend less time thinking of a solution.	Kotlin offers more laconic constructions, that enable the developers to code less and build complex solutions. Kotlin has a higher cognitive load, which requires developers to spend more time to find a solution. For abstract developers, Kotlin is certainly an ideal choice.
Stability	Java is an established programming language that offers long-term and end-to-end support for versions like Java 8 and 11. It means the developers and users will get complete support and fixes for any code-related issues in the future.  It also allows developers to download multiple versions of Java with a free license.	Kotlin is also a renowned programming language, but it is still in the emerging phase. Kotlin has no different versions, and it doesn’t offer long-term maintenance and support for developers and users.  As far as Stability is concerned, Kotlin is way behind Java.
Performance	Here the performance is quite good because the code compilation is done to ByteCode (which executes on JVM). Java also offers some additional features that make its performance better than Kotlin.	It also offers a Coroutines tool that enables developers to work with multithreading apps easily.  However, the performance of Kotlin code is a little slower than Java due to the availability of a plethora of features.
Popularity	Java is in the market for more than 2 decades, and undoubtedly it enjoys more popularity than Kotlin.  Although Java has seen many ups and downs, it consistently remains high on the popularity charts.	Kotlin is a comparatively new kid on the block, but it is gaining unprecedented momentum. It is touted as the language of the future and more organizations and developers are adopting it. Currently, it is behind Java, but its future looks extremely bright.
Community Support	Java enjoys the support of a massive developer community, where most of the developers come from India. This extends beyond India as well, as a large number of developers are learning Java, which makes the community stronger with each passing day.  This makes it easier to get a large number of documentation, additional features, plugins, and support for developers and users. Java stays ahead of Kotlin on this parameter.	Kotlin comes from Russia, and a large chunk of Russian coders have formed the core of the Kotlin community. Kotlin developer community is still in evolving phase and currently, it is 20 times smaller than Java’s developer community.
Talent pool	Java has been topping the list of the most-loved technologies for a couple of decades. It always remains in high ranking in Google Trends list. It enjoys the support of 44.1% of developers who are interested in developing class-leading apps with Java. However, it stays behind the Kotlin, which enjoys the support of a larger chunk of developers who adore it for their developmental needs.	According to the Stack Overflow survey, Kotlin is among the most popular programming languages, with the strong support of around 8% of professional developers preferring it over its competitors.  Kotlin enables developers to fetch more revenue of $55K per year, whereas it is $50K for Java.
Learning curve	Java comes with ample documentation and learning resources, that make it easy to learn for both experienced and newbies.	Kotlin requires more cognitive efforts in learning if we compare it with Java. Although it requires lesser code, that makes it easy for experienced developers to switch to Kotlin.
Libraries	Java offers a wide range of libraries, tools, and frameworks for android application development.	Kotlin lacks here but it is gradually catching up with the release of newer libraries such as Coroutines and KTX. However, it will take some time to give a tough competition to Java on this front.

Java vs. Kotlin – Use Cases

We have discussed the pros and cons along with the features of both languages. It’s time to explore the practical part of their usage. Although both Java and Kotlin are similar and offer somewhat similar capabilities, developers utilize them for different tasks and functions. 

Here we will provide you an insight into their real-world use cases so that you can decide which language is suitable for your project.

Why should we select Java?

There is no debate on the fact that Java is a universal programming language. A few years back, Java was used to develop standard android applications, but now the scenario has been changed completely. As technology is evolving, Java could be used to build complex eCommerce, BigData, and scaled enterprise systems as well. 

Java must be used to develop applications with a plethora of functionalities and features, that can function on all platforms (iOS, Android, Linux, or Windows) effortlessly. Java supports popular instruments for BigData like HBase and Hadoop. Technology organizations working on HDFS, MapReduce, and high-load servers prefer to use Java.

Major eCommerce companies use Java to handle their Rule Engine and BPM. Java offers JakartaEE, which allows enterprises to develop highly reliable and robust applications. Applications such as Netflix, Hybris, Apple TV, and ATG are developed using Java.

Why should we select Kotlin?

Kotlin is a preferred choice of mid-sized organizations and startups to build full-fledged Android applications. Kotlin is used as a base for most of the applications in the Google Play Market.

It is used to develop microservices and other complex components. Kotlin could be combined with Quarkus, Micronaut, and Spring Boot to develop modern and complex android applications.

Kotlin should be used to build high-performance applications. It is a preferred choice to develop an application that is platform-independent and could be cross-compiled for multiple platforms along with Android.

Android applications such as Pinterest, Coursera, Evernote, and Trello are developed using Kotlin.

Conclusion

For Android app development, Kotlin has emerged as the most suitable option now. Kotlin is growing exponentially, and it can be seen with increased adoption by many organizations and developers.

On the other hand, Java has established itself as a well-known, proven, and excellent general-purpose programming language. Java has been a primary language to develop Android applications and it will not be replaced so quickly, that’s for sure. 

We have offered a deep insight into both languages, and we are pretty much sure that it will help you to make an informed decision. However, at the end of the day, what matters is how comfortable your developers feel with either of these languages. 

As an android developer, you must be well-versed with Java, as it provides you with the required fundamentals to develop android applications.

But if you already have possessed enough expertise in Java, then you must go with Kotlin. It is undoubtedly the language of the future and will rule the android development paradigm in years to come.