Kotlin vs Java: What’s the Difference?

Kotlin vs Java: What's the Difference?
Kotlin vs Java: What's the Difference?

Introduction To Kotlin vs Java:

Evolving technologies have changed the way applications are developed, making them faster and more efficient, with lesser bugs and shorter time-to-production. Today, developers have a range of programming languages available to them, and they can choose whichever fits their requirements the best. 

Two programming languages have emerged among the top choices for developers worldwide for developing apps—Kotlin and Java.

According to StackOverflow, Kotlin was the fourth most beloved language in 2020 with 62.9% votes. At the same time, Java ranks among the top five programming languages used for Android application development.

Both Kotlin and Java are excellent programming languages, so choosing one can often be quite difficult for developers. The common questions developers have are:

  • Will Kotlin help improve Android app development?
  • Is Kotlin better than Java for Android app development?
  • Which programming language to choose for Android app development – Kotlin vs Java?
  • Should one migrate from Java to Kotlin?

Before you decide which one you should use, let’s understand each language. 

What is Java?

Java is a popular general-purpose, class-based, object-oriented programming language used by top organizations like Google, Instagram, Spotify, Airbnb, etc. It is the native language used by Android. Java uses a ‘Write Once Use Anywhere’ approach.

Using Java, one can create applications that use different operating systems and run on a single system or be spread across different servers and clients in the network.

What are the advantages of using Java for application development?

  • Java follows the object-oriented programming concept making it easy to create relationships between different objects in the application.
  • Java offers a range of useful libraries to users with which they can build any function they need to easily.
  • Since most hosting providers support Java, the language can offer a vast host of integration capabilities for users.
  • Java offers users the option to run applications in a ‘Sandbox’ using which they can reduce vulnerabilities to the application.
  • Java is a platform-independent language, so you can create it on one operating system, say Windows, and run it on another system that would support a Java Virtual Machine or JVM.
  • Java has very robust coding, and it is practically impossible for Java instruction to compromise your data or corrupt your system’s memory.
  • Java is one of the easiest programming languages to use, and even newbies can learn it very easily.
  • Java is an open-source language, so there is a high scope of flexibility and customisation.
  • Java has been designed as a distributed language, and it facilitates collaboration among users.
  • Developers can use Java without worrying about writing all the code manually for memory management.

What are the disadvantages of using Java for application development?

  • Compared to some other programming languages, the Java code is quite verbose and complex.
  • Learning the syntax for coding in Java can be a little tedious.
  • If some content is incompatible with the device being used, it would be impossible to access or use that content in Java.
  • Java sometimes interferes and hinders the Android API design.
  • Java follows test-driven development, which increases the possibilities of errors and bugs in the application.
  • Java eats up a lot of system memory and can slow down the system considerably.
  • Java is not as easy to upgrade, and users often stick to the version they have been using even when newer versions have come up.

What is Java used for?

Typical applications of the Java programming language include:

  • Android applications
  • Software products
  • Financial programs
  • Programs for data simulation and modelling
  • Platform-independent PoS systems
  • Stock trading programs

What is Kotlin?

Kotlin is a general-purpose, cross-platform, statically-typed programming language used by top organisations like Google, Netflix, Amazon, Trello, Pinterest, Uber, etc. Kotlin released a significant update recently in January 2021 that promised lots of important improvements in the language.

Kotlin is a rather new programming language on the block, and Java inspired its creation. Kotlin is clean, simple, easy, and less complex than Java and a lot of other programming languages. Any developer with a basic understanding of programming concepts and structures will easily use Kotlin for Android app development.

What are the advantages of using Kotlin for application development?

  • Applications can be deployed faster using Kotlin.
  • Kotlin helps control the size of the application being developed.
  • Kotlin code is much less verbose and less complex than that in Java.
  • Developers can make use of all the libraries and frameworks that have been built in Java.
  • Kotlin works to help reduce compile-time error detection.
  • Kotlin safeguards against the NullPointerException.
  • The arrays in Kotlin are invariant; this is not the case in Java.
  • Kotlin removes the boilerplate code and eliminates numerous errors.
  • Kotlin is completely free to use.

What are the disadvantages of using Kotlin for application development?

  • Kotlin does not have a community as diverse and strong as Java.
  • Kotlin has a rather tough learning curve and proves to be very challenging to migrate to sometimes.
  • Skilled developers well-versed in working with Kotlin are hard to find.
  • The initial code readability is not so high for Kotlin.
  • Kotlin offers limited resources for professionals wanting to learn the language.
  • Developers need to know Kotlin thoroughly before beginning to work on it or migrate to it.
  • Kotlin does not offer clean building as Java does.

What is Kotlin used for?

Kotlin is commonly used for:

Kotlin Vs Java: Which one should you choose?

FeatureKotlinJava
Interworking abilityYesNo
Offers incremental change of codeYesNo
Ease of migrationYesNo
Backward compatibilityYesNo
Requires lesser codeYesNo
More declarativeYesNo
Mixed language database capabilitiesYesNo
Active user communityYesYes

While Java has enjoyed considerable popularity until now, Kotlin is definitely the future language for enterprise applications and mobile development. Kotlin is already growing exponentially in the developer community, carving out its place as a preferred programming language.

With some of the largest organisations already making a move to Kotlin, it sure has a bright future and should be the language you should choose for your development tasks. 

Have a doubt in mind? Get it resolved from our video or mentors!

Frequently Asked Questions

Is Kotlin free to use?

Yes, Kotlin is completely free to use.

What are the business benefits of migrating to Kotlin from Java?

As Kotlin is largely interoperable with Java, it is relatively easy to migrate to Kotlin. Kotlin offers strong customer support, and developers who are well-versed with Java can jump over quickly.

Is Kotlin an object-oriented programming language?

No, Kotlin, unlike Java, is not a fully object-oriented programming language, but it has both object-oriented and functional constructs. If you are looking for an object-oriented programming language, Java could be one of the best options for you. Kotlin is a mix of functional and procedural programming.

Is Kotlin compatible with Java?

Kotlin is 100% compatible and interoperable with Java. Kotlin was built to ensure that the existing codebase of applications remains fully compatible with Kotlin. Java code can be called from Kotlin, and Kotlin code can be called from Java without a hitch.

Is Java free to use?

You generally do not have to pay for using Java unless you are looking for long-term support from Oracle.

Are Java and Kotlin open-source programming languages?

Yes, both Java and Kotlin are open-source programming languages.

Who has a bigger user and support community—Java or Kotlin?

Compared to Kotlin, Java has a much bigger and stronger user base and support community. Java is much older and much more widely used than Kotlin, a relatively much newer language on the block.

How does the future look for Kotlin?

Kotlin has expanded its footprint significantly over the past few years, and it will continue to do so in the future as well. Some large organizations have already migrated from Java to Kotlin, and more are joining the bandwagon. Kotlin has a bright future. Professionals wanting to learn Kotlin must begin now!

Key Takeaways

In the battle of programming languages, Java has always been a strong contender, but it is slowly conceding to Kotlin. Each language has its advantages and disadvantages, as we have shown above. 

Eventually, it all boils down to what the organization is looking for from its programming languages—what it wants to achieve, what is negotiable and non-negotiable for it, etc.

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Both Kotlin and Java are promising programming languages with excellent features for developers around the world. Pick the language based on your need.