Kotlin vs java has been one of the hot topics of debate for the last few years.

Ever since Kotlin was released in February 2016 programmers have been having doubts about which language to use for Android development.

Kotlin vs Java

Java has been around for a very long time. It is being used by millions of programmers worldwide but had some minor drawbacks. Then Google introduces a new language specifically for android which is said to be better than Java.

Last year, Kotlin has been made a ‘first class’ language for Android development by Google in addition to existing support for Java and C++. The impact of Google’s decisions for adopting Kotlin can be seen from GitHub’s findings.

The number of GitHub notes and contributors using Kotlin for projects has more than doubled over the last couple of years.

I’ve been making android apps using Java for about 4 years now and, I learned Kotlin just three months ago. While making an app in Kotlin, I quickly understood that there are many advantages of using Kotlin over Java.

Advantages of Kotlin over Java

Readability

Comparing to Java, Kotlin has more readable and precise code which makes it easier to understand the program. After a small learning curve, a Java developer can easily understand how to write Kotlin very quickly.

After learning Kotlin I observed that it needed much less code than Java as shown below

Java

Java readability

Kotlin

Kotlin Readability

As we can see, Kotlin reduces boilerplate as compared to java. Now, boilerplate refers to those codes which must repeat lots and lots of times and which do not serve any purpose to the functionality of the application. Kotlin has been designed in a way that it eliminates the need for boilerplate code.

Kotlin requires fewer lines of code as compared to java.

In Java, we must create references for views using findViewById. In Kotlin, that is taken care of automatically, therefore, reducing the lines of code drastically. That makes it easier for a beginner to learn Kotlin.

Null-Safe

Null pointer exceptions also referred to as “The billion-dollar mistake”, is one of the most common errors that cause apps to crash if you are using Java.

Kotlin is null-safe by default. It does not allow variables to be assigned with a null value. But in Java, we can assign null values to variables and, it may lead to null pointer exception that may crash the application.

Using Getters and Setters

In Java, we have to use getter and setter functions for receiving data from variables in the modal classes. Model classes are just used for holding data. We can use the getters and setters for accessing the data from model classes.

Using getters and setters

In Kotlin we don’t need all those getter and setter functions. We can access all the data’s using the variable name itself. See the example below.

Kotlin getters and setters

This modal class in Kotlin only has to define the variables instead of also defining the getter and setter methods. While comparing the above two images, we can clearly see that Kotlin uses less code as compared to java.

Interoperability

Kotlin language is interoperable. This means that both Java and Kotlin are somewhat similar and we can use java commands and Java libraries in a Kotlin project.

Since Java is still being used by most programmers, Kotlin has been made to be interoperable. It can be used with existing Java classes and won’t cause any errors. The compiler will allow the code containing the Java and Kotlin classes to work flawlessly.

Because of this feature, developers can transition from Java to Android with ease.

Immutability

An immutable object is an object whose state cannot be changed once it is created.

In Kotlin variables are defined using val or var to help developers easily understand which values can be reassigned.

Using val in our code makes it super clean and will be able to safely assume that the properties will never be changed and that they will not be null. The benefit is that it allows you to just get on with the project at hand.

Conclusion

I can confidently say, Kotlin language is far better than Java for Android development as it takes care of the drawbacks Java has. Moreover, the transition from Java to Kotlin is easy and anyone who is interested in programming can make good progress within a short span of time.

- Benedict Thomas