Kotlin vs. Java | Who wins the battle?

Kotlin vs Java

We know your pain; it’s not easy to choose between programming languages with little difference in the final output and main features between them. 

Kotlin vs. Java is one of the coding pairs that industry experts often compare. Those two languages can’t be used completely interchangeably. However, when it comes to choosing mobile development languages, many face the dilemma of which language to choose. 

To prevent you from hours of guesswork and confusion over the numerous features of Java and Kotlin, we combined here the key factors you should know. Read on, and let’s choose which one you should eventually learn (maybe both). 

What is Kotlin? 

Kotlin was launched in 2016, and it took just one year to establish itself as one of the most useful coding languages. In 2017, Google recognized Kotlin as their second official language for Android development. In 2019, things went even further, and Google announced Kotlin as the favored language for Android apps development. 

Kotlin is an open-source, statically typed, general-purpose language. Like Java, Kotlin can be described as a platform-independent language, as it compiles code to bytecode and, therefore, runs on any Java Virtual Machine (JVM). 

Kotlin is usually associated with mobile application development. However, its so-called mission is significantly larger than purely that. Kotlin was established with the vision to support mixed-language projects and heighten developers’ productivity. That’s why Kotlin’s founders enhanced it with concise abstractions and expressions and made him with an improved syntax. 

Why is Kotlin vs. Java so often compared?

The first and the most obvious reason is that you can use both languages for the same purpose: mobile app development. Beyond that, Kotlin has the same level of universality as Java, as it also runs on JVM.

Last but not least, though Kotlin is significantly younger than its peer Java, it was introduced to improve the existing coding experience. That’s why Android developers benefit when they combine the two languages and often compare which one is easier. 

What is Java?

We have previously discussed Java in detail, so here we will discuss only the key points you need to know in the context of Java vs. Kotlin. 

Let’s first start with the similarities. 

Java and Kotlin are both open-source, general-purpose languages, and both are pretty universal in terms of platforms they can run on. 

However, we can state that Java is an ancestor of Kotlin, as the latter came with many improvements that address Java’s weaknesses. 

Java was introduced in 1995, more than 20 years before Kotlin. Though there are new and updated versions for Java, it still lacks some features, such as extension functions, data classes, inbuilt null safety, etc., that Kotlin came to compromise for. 

If you are unsure what those features are used for, let’s jump into a more detailed explanation.  

Kotlin vs. Java | What does Kotlin have that Java lacks?

Null Safety

Assigning a null value to a variable is essential for Android applications, as the system heavily relies on null to quickly detect the absence of a value

Both Java and Kotlin allow developers to attribute a null value to variables; however, they do it differently.  

Java has a NullPointerExceptions by default, which opens an exception every time a developer tries to assign a null value to the variable which already has a null value. Further, developers need to handle the exception and figure out the issue, often becoming a headache. 

In the case of Kotlin, there are no NullPointerExceptions, which means null values are not assigned to a variable by default. If a developer wants to do that, they can explicitly mark the variable in question as nullable. 

Extension Functions

Extension Functions allow the developers to add new functionality to the class, and you can do this with both languages. However, in the case of Kotlin, you can do it easier and quicker. 

To extend a function in Java, one needs to create a new class and inherit the necessary functions from the parent class

To perform the same task in Kotlin, developers would prefix the name of the function and the name of the class that they want to extend. To do that, developers need ‘.’ notation. 

Data Classes

Kotlin has the specific class that holds data, whereas developers should create certain fields to do that in Java. As a result, storing structured data in Java requires a significantly longer time than Kotlin. Let’s explain in more detail. 

In Java, developers add constructor, getter, setter, and other functions to create variables to store the data. And though developers spend sufficient time on that, those variables perform no other function than just storing data. 

In Kotlin, things stand easier. If a developer wants to have a class that will hold the data, they will add the “data” keyword in the description of the class. 

Verdict on Kotlin vs. Java

Most developers agree Kotlin introduces solutions to issues of the Java ecosystem. Kotlin is cleaner and lightweight and allows performing most Java functions easier and quicker. 

However, though Kotlin exists to improve Java developers’ opportunities, Java is not leaving the stage. It’s still one of the top languages to learn. According to programming language tutorial searches on Google, Java is the second popular language

To sum up, if you have the proper level of skills and competency in either of those languages, you will find your place in the Android application development market. However, if you can learn both and combine the functionalities of two languages, even better!