For a long time, Java was the beloved language of programmers, However, after the arrival of Kotlin, the popularity of Java is somewhat shaken. After all, Kotlin was invented to resolve the numerous issues with Java. For instance, Kotlin eliminates the need for checked exceptions, arrays have invariance in Kotlin as opposed to Java, Kotlin is devoid of raw types, the language authorizes any null references present, Kotlin incorporates string templates, string casts, primary constrcutors, and extension functions, and Wildcards in Kotlin are not needed to deploy or utilize site variance. In order to resolve the biggest question of Kotlin vs Java, we are elucidating the differences between the two to help you decide whether to use Kotlin or Java for your next development project:
What is Java?
Java is an object-oriented programming language, which is preferred by developers all over the world when it comes to Android applications since it is easy to create modular applications from Java and reuse existing components. Signal, Cash App, Twitter, Spotify are some of the most popular applications of Java. Java is mostly used for back-end development, mostly to develop standalone applications. Programs or applications developed in Java execute in a Java virtual machine, which allows us to run the same program on multiple devices and platform. The best thing about Java is that it is multiplatform, which means it works on all OS and devices. Since Java coding is robust, Java instruction cannot compromise data from other OS applications or even corrupt memory. If we compare Java to other programming languages, Java is relatively easier to use, debug, compile, and reuse.
However, like all Programming languages, Java has its quirks. For instance, the syntax used by Java can prove to be more intricate than other languages, not to mention, it isn’t a piece of cake to access the new Java enhancements in mobile app development. In addition, Java takes up a lion’s share of system memory and is slower than other programming languages. Also, Java can cause issues with the Android API design. Code written in Java is much more prone to errors and bugs than code written in many other programming languages.
What is Kotlin?
However, Kotlin has a few quirks of its own just like any other programming language. For instance, Kotlin isn’t the A-lister as compared to more well-established programming languages like Java, which gives it a smaller developer community. And since it is hard to come by Kotlin developers in the market, you will be hard pressed to find an experienced mentor. As compared to Java, Kotlin has a steeper learning curve due to its concise syntax, which is why developers find it hard to switch to Kotlin. Since the language is much younger than Java, it also has less tutorials, blogs, and libraries around it. Also Kotlin has a more complex code readability, which makes it harder to read and understand.
What is The Difference between Kotlin vs. Java?
Java vs Kotlin: Checked Exceptions
Since Kotlin has no provision for checked exceptions, you don’t need to declare or catch any exceptions. On the other hand, Java incorporates checked exceptions support which enables developers to declare and check the exception, resulting in a robust code with good error handling. If a Java developer is finding it tiresome to use try/catch blocks in the code, then switching to Kotlin offers a nice change. However, if you are of the opinion that checked exceptions result in a more robust code, then you should stick to Java.
Java vs Kotlin: Smart Casts
Java makes it mandatory to check type before an object can be cast. On the other hand, Kotlin has smart casts features where all redundant casts are automatically handled. In Kotlin, there is no need to cast inside a statement if it is already checked with the ‘is operator’.
Java vs Kotlin: Null Safety
NullPointerExceptions are the bane of every Java developer. Java developers are allowed to assign a null value to any variable, since Android uses null to represent the absence of a value, but when they use an object reference that has a null value, the NullPointerException can easily destroy an app. Kotlin comes to the rescue with an inbuilt null safety to save developers the hassle of writing extra code to circumvent the issue. By default, all types are non-nullable in Kotlin, so even if a developer assigns null values to any type of variables/objects in the Kotlin code, it will not work at compile time. However, if you do need to assign a null value to a variable in Kotlin, you can do so by explicitly marking that variable as nullable via adding a ‘?’ sign after the type.
Java vs Kotlin: Extension Functions
Unlike Java, Kotlin lets us extend a class with new functionality without inheriting from them, through extension functions. Unfortunately, this feature is not available in Java. In order to create an extension function, simply prefix its name with a receiver type, or more precisely, the name of the class that needs to be extended. On the other hand, if you wish to extend the functionality of an existing class in Java, you need to create a new class and then inherit the parent class.
Java vs Kotlin: Coroutines Support
Whenever you initiate a CPU-intensive or long-running network I/O operation, Java automatically blocks the corresponding thread. Since Android is single-threaded, an app’s UI gets completely stuck as soon as the main thread is blocked. Java lets developers create multiple threads but running and managing multiple threads can prove to be more complex than you imagine, not to mention, there is a higher possibility of errors. While Kotlin also gives you the ability to create multiple threads to such long-running intensive operations, they can be easily managed with the help of coroutines support. Being stackless, Coroutines require lower memory usage as compared to threads. Instead of blocking the threads, Caroutines support long-running and intensive tasks by suspending execution and then resuming it at some later time.
Java vs Kotlin: Data Classes
If we have a Java class which needs to hold data but nothing else, you need to write a lot of boilerplate code in Java, such as variables to store data, constructors, getter and setter methods, hashcode(), toString(), and equals() functions. But on the other hand, creating such classes in Kotlin is relatively easier. All you need to do is to declare a class with keyword “data” in the class definition, and the compiler will do the rest!
Java vs Kotlin: Security
If you compare the security of Java and Kotlin, Kotlin takes the prize since it is prone to crashes as compared to Kotlin. Being more flexible, Kotlin results in a more succinct code, which reduces the likelihood of bugs and errors. However, Java is also a highly secure language, since the Java Virtual Machine takes care of security at each stage, at the time these byte codes are executed. JVM is an interpreter that is continually fortified with the most up-and-coming security updates. As compared to other programming languages, Java is relatively more secure, due to access control functionality, use of final word, exception handling, data hiding capability of OOP, no access to memory management, and non-reliance of pointers to prevent unauthorized access to the memory block.
Java vs Kotlin: Interoperability
Kotlin was designed with one purpose in mind: Interoperability. Code written in Kotlin may look feel slightly different to Java programmers, but in reality, it is not so different in functionality. In fact, Kotlin is fully compatible with Java, since it compiles to the exact same bytecode and has total access to all existing Java libraries and frameworks, even those have advanced prerequisites or require annotation processing. You can run Kotlin code on both JVM or on Android. Kotlin code is free from adapter layers and wrappers, alleviating the need for you to rewrite any piece of code by hand. Any modules you write in Kotlin will be able to flawlessly integrate in your existing Java code. When the bytecode is eliminated, Java and Kotlin can work together in unison via the Kotlin compiler, allowing you to work on your existing Java projects. The best part about using Kotlin is that you can still access your favorite Java frameworks as well as those offered by Kotlin. Talk about the ‘best of both worlds’!
Java vs Kotlin: Multithreading
Creating too many threads impose overhead when it comes to garbage collection and object allocation, which can slow down an app. Kotlin has multi-threading capabilities, which translates to the fact that it supports concurrent execution of multiple parts of a code to make the best use of CPU. Each part creates its own thread, which is basically a light-weight process within a process and the smallest unit of processing. Kotlin enables multi-threading through implementing runnable interfaces, extending thread class, and via Lamba expressions. The best thing about threads are that they are independent objects, which means that an exception in one thread doesn’t affect other threads, but the problem is that threads uses a shared memory area and are executed within the process. There can be more than one process running concurrently inside the OS and even one process can have different threads. Java allows context-switching between threads, so that multiple threads can be executed at the same time. Multi-threading in Java leads to multi-tasking, since multiple operations can be performed simultaneously, an exception in one threads doesn’t affect the others, and threads are fully independent of each other.
Java vs Kotlin: Performance
There is an ongoing ‘Kotlin vs. Java performance’ debate online, but the truth is that there is no such difference between the performances of the two. As an estimated, Kotlin averages 18.5 seconds at compilation time, while Java fares slightly better at 15.5 seconds. Java performs better than Kotlin for clean code but Kotlin shows better results for incremental compilation.
Java vs Kotlin: Customer Support
Between Kotlin vs. Java, Kotlin has a strong customer service team with a solid reputation, which translates into less downtime.
Java vs Kotlin: Community
Being a newer language, Kotlin is prone to information gaps, which can make it difficult for programmers to solve unprecedented challenges and problems. While more information is being added by the day and the community is certainly thriving, it still fades in comparison to a more classic language like Java. This could create problems for developers who get stuck with a problem in Kotlin.
Is It Necessary For Developers To Learn Kotlin?
There are quite a few mixed opinions about this. While Java developers are not necessitated to switch to Kotlin, but Google I/O has recognized Kotlin as one of the officially supported languages for application development in the Android domain, which means that they will have to encounter the language one day or another. Not to mention, if you have got to grips with Java, you will no difficulty whatever learning Kotlin. A lot of new futures are exclusive to Kotlin, such as availability of primary constructors and null-safety, presence of smart casts, extension functions, caroutines, companion objects and string templates, delegation available of the first class, and presence of various data classes and multiple types of range operation, so it doesn’t hurt to learn the language. Kotlin is the future of Android app development, so if nothing else, it will add to your skillset as a developer. If you’re starting a new project, you will find that Kotlin is much less verbose–less code to type, test, and maintain.
The Business Benefits of Switching To Kotlin
Redoing large portions of a project in a new programming language is a serious decision; however, Kotlin offers two indispensable business benefits impacting the decision.
Reduced Project Timeline
The succinct nature of Kotlin’s code is greatly beneficial for businesses. Less code means less time in development, less modification, less reviewing, and less bugs. This empowers businesses to cut down on project development time and cost, giving them an edge in the competitive business market.
Fewer App Crashes
With fewer lines of code as compared to Java development, code written in Kotlin is also easier to maintain. The enhanced readability of the language as well as less code for bugs to hide, makes it easier for your QA team to locate bugs in time, thereby resulting in less system failure and fewer app crashes.
Enhanced Product Quality and Support
Java’s extensive coding means more surface area for bugs and errors. Not to mention, developers have to waste a lot of time going through elaborate pieces of code to locate the errors. The lengthier the code, the more difficult it is to locate the hidden error. On the other hand, it is much easier to locate the bug inside the succinct Kotlin code and provide long-term support. A shorter code also gives developers a greater sense of clarity and control during the app development process, leading to cleaner and more efficient interfaces.