Kotlin vs Java

Choosing the best among programming languages to develop applications has always been a rough call for most developers. Java is considered to be unmatched everywhere. However after the arrival of Kotlin, programmers have always had doubts about whether to choose Java or Kotlin in their development.

What is Java?

Java is a native programming language. It is used to communicate with the Android operating system. It supports Android, OSX, Windows & Linux. It is an object oriented programming language and also considered one of the most popular languages.

What is Java

Advantages of Java:

  1. There are very low chances of memory corruption or compromised data in the case of Java vs Kotlin, thanks to its robust code.
  2. Since Java is an object oriented programming language, it makes creating modular apps easier than expected.
  3. Java is designed to work on all the existing operating systems, devices or servers.
  4. Java makes compiling code, debugging and deploying apps easy with proper functionality when compared to Kotlin.
  5. With Java’s community support, you can find lots of third-party code which is ready to be used on your app.
  6. The open source language is used by giants like Apache, Google etc. so it feels safe to use the libraries of Java.

Disadvantages of Java:

  1. Writing Java’s syntax can get complex in comparison to languages like Python or C+.
  2. Java sometimes has clashes with Android’s API which can lead to problems.
  3. Using Java to get content that is incompatible with the current device is almost impossible.
  4. Java’s new updates for mobile development are hard to access.
  5. Java uses up a lot of device memory and performs slower in comparison to some other languages.
  6. TDD or Test Driven Development in Java has higher chances of bugs along with extra lines of code.

Apps made using Java:






What is Kotlin?

Kotlin is an upgraded version that is inspired from Java which adds many features that give it an edge of Java. Kotlin is clean, simpler than Java which has less rules than Java and other languages. For learning Kotlin to build apps for Android, one needs to still understand basic coding concepts which are vital to get around with Kotlin. 

What is Kotlin

Advantages of Kotlin:

  1. Kotlin code is compiled faster, it is very much lighter and restricts applications from expanding on storage since install.
  2. Java’s code always has longer syntax than Kotlin as Kotlin uses lesser code. This means lesser changes of bugs.
  3. Kotlin code is compiled to bytecode. This bytecode can be run in the Java Virtual Machine, which allows Java frameworks and libraries to be migratable to projects created using Kotlin.
  4. NullPointerException is safe while using Kotlin
  5. Kotlin projects can be configured to use auto-complete for syntax which helps a lot to reduce compilation errors.
  6. Coroutines are usable with Kotlin while interoperability with JavaScript is also a feature.

Disadvantages of Kotlin:

  1. Kotlin has a lesser user base and smaller community since it is a new language.
  2. The Kotlin community support is sprouting, there are fewer libraries and tutorials in Kotlin than Java.
  3. Unlike Java, Kotlin’s learning curve is steep and switching over to Kotlin for having a project with lesser code would be hard for teams starting out.
  4. Finding Kotlin developers around the market is a hard job.

Apps made using Kotlin:






Feature Comparison – Kotlin vs Java: 

  1. Compilation:

Kotlin compiles through a JVD which is a virtual machine while Java uses bytecodes to compile syntax

  1. Null Safety:

Java includes a class for null safety by calling errors before building while Kotlin uses built-in variables to provide null safety

  1. Lambda Expressions:

These are similar in both Kotlin & Java but Kotlin uses curly braces which help to make the syntax more readable.

  1. Classes:

Kotlin has data classes to set/get while Java uses private variables in classes to set/get. In Kotlin, data classes enable parameters of the class to be exposed and directly accessed.

  1. Concurrency:

When it comes to concurrency, Java has multi-threading while Kotlin comes with coroutines.

  1. Extension Function:

Kotlin introduces this to use classes with more functionality without extending them.

  1. Community:

Java still keeps the higher position when it comes to community making it always easy to grasp or get help from fellow developers.

Differences in Kotlin vs Java

  1. NPE

NullPointerException is a huge disadvantage of Java. This is caused in initialization where there are potential errors of data initialization. Kotlin gives an early error during compile time which helps build bug free applications.

  1. Syntax for Classes

The amount of code that Kotlin saves in comparison to Java is huge. For example, defining a class in Java takes about 50 lines of code while Kotlin has a one line data class initialization syntax which shows the potential difference between them.

  1. Code Review

Kotlin focuses more on syntax readability which allows project members to review the code without actually knowing the language.

  1. Type Interface

Kotlin does not require you to specify the type of variable explicitly while allowing users to optionally define specific variables whenever they wanted to. 

  1. Limitations

Java restricts users limiting them with design errors and its boilerplate code which makes writing in Java less fun. Kotlin on the other hand simplifies code using features like type check and casts.

  1. Compilation

Java has a faster compilation speed than Kotlin even if there are few exceptions.

  1. Resources

Finding resources to learn Kotlin would be a bit harder than Java since it is a new language. This may not be the case in the future as the bubble of Kotlin is expanding.

  1. Autocomplete

Kotlin has known issues for being slow when compiling code or using autocomplete in Android Studio.


These are some features that help identify which programming language you can go for. Although Kotlin has some powerful features, Java still has its place as the community is huge. On the other hand, it is easy to learn Kotlin coming from Java as Kotlin is represented as an enhancement from Java. Altogether both the languages deliver quality applications whatsoever with the pros and cons they have.

By admin