Kotlin vs. Java: Which is Better for Android App Development?

Java has long been the programming language of choice for building functional, feature-rich, and user-friendly Android apps. Until Kotlin made its grand entry in 2016, developers were quite comfortable with Java.

Now, anyone planning to enter the Android app development scene faces a significant dilemma: Kotlin vs. Java, which is better for Android app development?

For starters, both Kotlin and Java are excellent for building high-quality Android apps. Both of them are object-oriented programming languages and are known for their superior features and functionalities.

According to a 2022 developer survey, over 33% of developers use Java and over 9% of the community uses Kotlin.

Though Java seems to be the clear winner here, Kotlin has an impressive market share considering that it is still only a few years old. Over 20% of the active apps in the Play Store today have been developed with Kotlin.

While both of them are great, you cannot use a combination of Kotlin and Java in the same app. To help you pick a side in the Kotlin vs. Java debate, we will provide you with all the relevant information on both.

Here’s a quick summary of both of these programming languages.

Parameters	Kotlin	Java
Performance	High Level	Almost the same
Popularity	Moderate Level	Extremely Popular
Ease of Use	Easy	Hard
Scalability	High Level	Moderate Level
Documentation	Good but hard to understand	Good and easy to understand
Cross-Platform Support	Supports multiple platforms	Supports limited platforms
Community Support	Moderate Level	High Level

 

 

 

 

 

 

 

For those, who want a more fleshed-out comparison of the two, here’s a lengthy and more detailed version. Let’s get started!

Kotlin vs. Java: Starting with the Basics

Java is a robust and powerful object-oriented programming language used for several purposes including Android app development and management. It has been 26 years since Java was launched, and it continues to thrive with a huge market share. Most of the features of Java are available in open source.

One of the reasons developers use Java to build Android apps is because it is platform-independent, which means the apps can work on any platform. Furthermore, Java has its own API and runtime environment (Java Runtime Environment).

A large number of Android apps are built on Java. As you can see in the graph below, Java has been one of the most widely used programming languages for more than 20 years. Though its popularity has gone down a bit since 2020, it is still in the top 3 most used programming languages for Android development.

What is Kotlin?

Kotlin is a statically typed, cross-platform programming language, which can be compiled into JavaScript. It can run on both a Java virtual machine or JVM and browsers. Android developers can write the code in Kotlin and then use an IDE for building cross-platform apps.

Developed by JetBrains, Kotlin was originally designed to make coding in Java more productive. But by 2018, it evolved as its own programming language, and with Google’s support, it was introduced as the alternative to Java for Android development.

In fact, Google officially made Kotlin the recommended programming language for Android app development with its Kotlin-first approach. Since then Kotlin’s popularity has grown significantly. Today, 87% of the top 500 apps in the US are made with Kotlin.

Kotlin vs. Java: Comparing Their Features

The Kotlin vs. Java debate isn’t as straightforward or simple as we might want. Both of them have their unique merits and both are great for Android app development.

So, how can you decide whether you should hire Java developer from India or hire someone who specializes in Kotlin?

To make an informed choice, you would need to compare their features and see which one fits your project and development needs the best.

Here’s a quick table that should offer some insight.

Features	Kotlin	Java
Extension Functions	With Kotlin, programmers can add new functionalities to existing classes. They can develop extended functions by prefixing the name of a particular function as well as the name of a class.	Java developers need to develop a parent class and a new class to extend the functionality of the remaining class. Sadly, extension functions are missing in Java.
Static Members	In Kotlin, static members of a class can be created by using the companion object. Developers can also mark an object declaration inside a particular class with the companion keyword.	Static members are available in Java, and they are used primarily for memory management. Developers can apply Java static keywords with nested classes, blocks, methods, and variables.
Null Safety	Kotlin has non-nullable variables, which means they cannot be assigned to a null value. The Kotlin code fails if developers try to assign, develop, or return null values. To print the null value for a variable, developers need to use the declaration “value num: Int?=null”	NullPointerExceptions have long been a source of frustration among Java developers. It allows them to assign null to variables, but it throws a null pointer when developers try to access an object reference with a null value.
String Templates	Kotlin has two types of string literals known as a raw string and an escaped string. Kotlin string template supports expression.	String templates are available in Java, but they don’t support expressions like Kotlin does.
Wildcard-types	Wildcard-types are missing in Kotlin, but it has type projections and declaration-site variance.	Available in Java, wildcard ? is a special type argument. It controls the type safety of the parameterized (generic) types.

Kotlin vs. Java for Android App Development

We can discuss and compare the features of Kotlin vs. Java all day long, but that may not satisfactorily answer which is better for Android app development. So, let’s discuss how they differ in terms of Android app development.

Ease of Use:

The first thing you need to address in the Kotlin vs. Java debate is that Kotlin is far easier to learn and use than its counterpart. With its collection of IDEs, tools, and tutorials, Kotlin makes Android app development fairly easy.

Java, on the other hand, is fairly difficult to learn and requires more code writing than Kotlin. But it has a thriving community and beginners can find all the necessary documentation to learn the language properly.

Performance:

Comparing performance in terms of memory usage is difficult since both programming languages compile to ByteCode.

But with all its extra features, Kotlin is more functional than Java. Furthermore, Kotlin’s Coroutines tool makes it easier for developers to work with multi-threaded applications.

On the other hand, Kotlin executes and compiles a bit slower than Java, which is primarily because of its extensive features. Java has fewer features than Kotlin, which means it compiles faster.

However, the difference is so slight that the battle of Kotlin vs. Java in terms of performance comes to a draw.

Stability:

There is a significant difference in stability between Kotlin and Java.

Since Java has been around for over two decades, developers have access to long-term support for previous versions. That means if anything goes with older versions, developers can find a patch for it.

Kotlin, on the other hand, is much younger than Java. It does not have any version with long-term support. Though both Kotlin and Java are considered to be stable, Java gets an additional point for stability.

Wrapping Up the Debate over Kotlin vs. Java for Android App Development

Choosing a side in the Kotlin vs. Java battle is hard. They have similarities and differences, and they are both suited for different tasks.

On one hand, Java has been around for longer and is used for building a large number of Android apps. On the other, Kotlin is fast emerging and slowly taking over the Android app development market.

Ultimately, the choice between Kotlin and Java depends on the developer. If you are a beginner, you may be safer with Java even though it has a learning curve.

Experienced developers with good cognition may choose Kotlin as it requires less code writing and is more visual.