KOTLIN VS. JAVA: What to choose for an Android App?

When Google announced Kotlin as the most preferred language for Android Development, the language debate reignited.
Soon the debate transformed into a boxing match wherein a young and elegant contender tried to take the title from a seasoned and experienced champion. But is Kotlin better than Java?
Java is the best programming language for many of us as it has a huge market penetration. However, this apparent belief has shaken, and the predicament is between Kotlin and Java for app development.
To resolve this dilemma, in this blog, we will discuss Kotlin vs. Java for app development and how one precedes the other. Let’s dive into it!
Introduction to Java
Java is a class-based, object-oriented native programming language developed by Sun Microsystems in 1995. Java is designed to lessen implementation dependencies and supports almost all types of Operating Systems, be it Android, Windows, or Linux.
One of the major advantages of this language is its portability. It is easy to write the code and seamlessly move it to another device. It can be used as a server-side language for android development, desktop computing, back-end development, and numerical computing.
● Java is the second most popular programming language of 2021 as per the PYPL index.
● The popularity of Java can be gauged by the fact that 90% of all Fortune 500 companies use Java
● Global companies such as Spotify, Twitter, Signal, and LinkedIn use Java.
Key Features of Java:
Java, the age-old programming language, has some features that get it to the top of the list every time. Let’s have a look at some of these features:
- Multithreaded
One of the best ways to create an efficient performance application is utilizing multithreading. Java supports multithreading that allows us to execute multiple threads simultaneously for making optimal use of the available resources. This assists the company in diligently positioning their employees when they hire android app developers.
2. Memory Management through Garbage Collector
Developers working in an android app development company worry about allocating and deallocating memory in their code. But with the garbage collector, the memory gets collected automatically by identifying the unused objects created on the heap and deleting them. This makes it convenient for businesses who want to flourish their mobile application development company rather than focusing on managing memory manually.
3. Platform independent
The magic of Bytecode makes Java platform-independent. The inherent advantage of platform independence is that the Java compiled code can run on all the operating systems. Java is like a write once, run anywhere type of programming language. This feature accelerates the working of an android app development company as the developers can start coding in Java and then switch to Kotlin for handling multiple android app development projects.
4. Robust for handling run-time errors
Java provides an expectation handling system that identifies and eliminates run-time errors. Unlike other programming languages, Java never passes the run-time error directly to the underlying system. Rather immediately terminates the program and cease it from causing any harm to the underlying system.
Introduction to Kotlin
Kotlin is a statically typed open-source programming language developed in 2010. Kotlin is an improved version of Java but with varied additional features.
Kotlin is a mix of object-oriented and functional programming that is clean, simple, and fast to compile for any android app development company. Furthermore, Kotlin can be used on Android, iOS applications development projects, or desktop apps for any development — client-side, server-side, or web.
● According to StackOverflow, Kotlin was the 4th most loved language with 62.9% votes in 2020.
● After the first official 1.0 release in 2016, Kotlin is now used by 8.32%(as of 2021) of the developers worldwide within 5 years.
● Global companies like Google, Netflix, Amazon, Trello, etc., use Kotlin.
● Recently, Pinterest and Uber migrated their android application development language from Java to Kotlin.
Key Features of Kotlin:
Kotlin has emerged as the new programming language that offers developers a lot more features than Java. Some key features of Kotlin are
- Interoperable with Java and Android
Kotlin is 100% interoperable with Java and Android and was announced as a first-class language for writing Android apps by Google. This implies that existing Java code can be called from Kotlin, and developers can continue to write Android apps using their current programming language. After looking at their requirements, some developers use Kotlin and Java for app development to create efficient android apps.
2. Create Domain-Specific Languages(DSL)
Kotlin has properties to create Domain-Specific Language(DSL) that extracts a part of code to make it more understandable and reusable. This makes the code readable like a spoken language so that people who don’t understand the architecture behind the code can easily grasp the intended meaning.
3. Collection Filtering
When working with an API, developers constantly deal with collections that need to be modified or filtered. But by using Kotlin’s collection filtering feature, the code can be made more concise and clear and can confirm the content of the resulting list. This feature facilitates sorting out a list to its proper display elements.
4. Smart Cast Function
Kotlin is quite intelligent when it comes to casts because it identifies the type of function, performs all the operations coded for a specific type, and enhances the efficiency of the code. For instance, the identification of a string becomes simple through the smart cast feature. The reason is that you just simply copy, count the length, identify the string, and perform various operations on the string type.
Kotlin vs Java comparison
Having looked at the features, you might have gotten a brief idea about the intricacies included in Kotlin and Java for app development. With the detailed comparison, you’ll get to know how one programming language has the edge over the other.
- Null safe
In Java, NullPointerExceptions cause huge frustrations for developers. Java permits users to assign null values to any variables, but while accessing an object reference having a null value, Java raises a null pointer exception which the user needs to handle. This makes the entire process cumbersome.
By default, all types of variables are non-nullable in Kotlin. If we try to assign or return null values, the code will fail during compile time, and you won’t encounter NullPointerExceptions error messages.
2. Extension Functions
In Java, if we want to extend the functionality of an existing class, we need to create a new class and inherit the parent class. Therefore, extension functions do not exist in Java.
On the contrary, Kotlin provides developers the ability to extend the functionalities of an existing class. In Kotlin, we can create extended functions by prefixing the name of the class to the name of the new function.
3. Checked Exceptions
Java has checked exceptions support which makes developers declare and catch the exception, ultimately leading to a robust code with good error handling.
Kotlin doesn’t have checked exceptions to aid code conciseness. So, developers don’t need to declare or catch exceptions.
4. Data classes
In Java, if we need to have a class that needs to hold data but nothing else, we need to set up fields or variables. For this, we need to define variables to store the data, constructors, getter and setter methods, hashcode(), toString(), and equal() functions.
In Kotlin, if we need classes to hold data, we can declare a class with the keyword ‘data’ in the class definition. Then the compiler will take care of all the other work, such as creating constructors, variables, and getter and setter variables for different fields.
5. Type Inference
In Java, we need to specify each variable’s data type explicitly. This makes the entire process arduous for a developer working in an android app development company.
In Kotlin, we don’t need to specify each variable’s data type explicitly. Each variable’s data type as the programming language will handle it based on the assignment.
6. Coroutine Support
In Java, whenever we initiate a long-running network CPU or I/O intensive operations, the corresponding thread will get blocked as android is single-threaded by default. Though Java provides the function to create multiple threads in the background, managing them becomes a tedious task.
Through the coroutine support of Kotlin, we can create multiple threads that help run these long-running intensive operations. Kotlin is not bound to a particular thread as they are not managed by the operating system but by the Kotlin run-time.
Comparison table
Yes, Kotlin is statically-typed, robust, and much less verbose than Java but does that make it your first choice for Android Development? We have compared Kotlin and Java for app development based on different parameters to give you a clear distinction between both programming languages.

Which one is better for an android app?
Kotlin and Java for app development are superior in their domain and offer a range of benefits that would make them an impeccable choice for developing mobile applications. However, if you’re looking for more specificity, then there are certain types of apps where one has the edge.
Java is preferable for:
● Large applications that incorporate varied clusters of features and functionalities that need to function across all the platforms. Java is suitable for this as it has mature libraries that support this type of app development.
Kotlin is preferable for:
● Applications where performance matters a lot, for instance, apps that support photo editing or those that need to run seamlessly on an older Android phone. This is because Kotlin has a more streamlined design than Java, and it will perform better where scaling is a concern.
● Apps that need platform independence and must be cross-compiled for multiple platforms function well with the Kotlin programming language. Kotlin can perform these functions effectively instead of Java as Java uses bytecode which can only compile code for one specific platform at once.
Conclusion:
To use Java and Kotlin programming languages efficiently, hire an android app developer from a company that provides the best assistance to hire mobile app development services. By doing so, you can build an impactful and multifaceted Android application.