Kotlin vs. Java in Android App Development
Java has been a reliable language used in Android app development for years, but with Kotlin's popularity on the rise, we must question which is truly better.
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Kotlin vs. Java is a topic discussed as hotly among developers as the perennial Android vs. iOS debate. Today, we will try to find out definitive answers to this question.
As a veteran app developer myself, here is what I have learned about programming. No language can be said to be easier or better in terms of readability because it depends on the code reader’s proficiency and the code writer’s clarity. When I began researching the difference between Kotlin and Java and discovered articles claiming Kotlin is easier to read and better to write than Java, I was surprised. Most, if not all of the comparisons were lopsided as they only discussed the features of Kotlin that Java didn't have. Because I couldn't find any reasonable answer myself, I decided to find the solution to this conundrum myself.
With this information piece, I intend to help you make the right call. And that is possible only after we have a fair comparison. Before we move on to the straight head-to-head comparison, let us take a quick look at the languages.
Kotlin: An Introduction
Popular Apps Made With Kotlin
Some of the popular apps made using Kotlin include:
A lot of other giants are also considering migrating to Kotlin from Java or other languages.
Because Kotlin is a fairly newer language as compared to Java, a lot of questions surround it — and in an effort to clear the doubts that many beginners (and even pro) developers might have, here are a few Kotlin FAQs answered.
Should I learn Java before Kotlin?
If you are an experienced developer and know the basics of mobile app development, then you can probably begin learning Kotlin without being an expert in Java. However, if you are new to the world of mobile app development, learning Java before jumping into Kotlin will likely be beneficial.
Can I Also Use Kotlin for Web Development?
Kotlin is a full-stack solution, so yes, it can be used for web development as well. You can also use Kotlin on the server, and it is able to be used both on the frontend as well as backend.
Are Kotlin and Java the Same?
Of course not! If that were true, we wouldn’t need to be having this either-or discussion. Kotlin and Java are certainly similar in some aspects — but they are different in terms of speed and performance.
Java: An Introduction
Java is an object-oriented programming language that was released in 1995 by Sun Microsystems, a property of Oracle. A large portion of Android apps, as well as Android itself, are based in Java. That is what makes it one of the top choices for any Android app developer. Additionally, most elements of Java are open-source, which allows for easy development.
Popular Apps Made with Java
Some of the popular apps made using Java include:
- NASA WorldWind
Now, let us understand the difference between Kotlin and Java on the basis of some of the features.
Speed of Coding
One of Kotlin’s main advantages is its brevity. To get a job done quickly, you can write way less code in Kotlin than to accomplish the same end goal in Java. This means you’ll be able to write Kotlin code more quickly.
However, with Kotlin, you may have to spend more time thinking of the solution. With Java, that time is minimized. This is why it may come down to each individual coder to choose which language is actually faster for them to code personally.
Performance and Functionality
While both the languages compile to ByteCode that runs on JVM, and their memory usage cannot be compared, Kotlin is indeed more functional.
To give you a clear picture of Kotlin vs. Java performance, here I have compared a few features of both:
- Java offers checked exceptions, but Kotlin doesn’t.
- Kotlin has Coroutines; Java doesn’t.
- Kotlin also offers extension functions.
- Higher-order functions and Lambdas come in-built in Kotlin. And you don’t have to deal with Retrolambdas. In Java, you will have to implement higher-order functions with callables. And lambdas were introduced in Version 8.
- Kotlin offers native support for delegation. And inline functions too.
- Java has non-private fields and NullPointerExceptions; Kotlin doesn’t.
- Kotlin doesn’t have static members like Java, but it offers companion objects in its place.
- Kotlin is null safe.
- Java doesn’t have smart casts, but Kotlin does.
There are a few features of Java that Kotlin lacks. But if we take an overall look, Kotlin emerges as a winner in the performance category for developing Android apps.
Kotlin is a fairly new language with no versions that come with long-term support. However, with Java, versions like Java 8 and Java 11 come with long-term support. This means that if these versions face issues, the original developers will use a patch to fix it.
So, as far as stability is concerned, Java is a clear winner. Though you cannot call Kotlin an unstable programming language, it is still behind Java in this one.
Oracle’s official documentation about Java is enough for you to learn Java. Also, because it’s an older language, tutorials, books, and guides are easier to find.
Kotlin also has good official documentation. However, you might have to dig a little deeper to find more resources because it is a comparatively younger language.
Java is a significantly older language, and thus, it has a broader community of developers as compared to Kotlin. However, Kotlin is much more loved by developers (62.9% of developers loved Kotlin as opposed to 44.1% of developers who said they loved Java, a survey suggests).
With this knowledge, you can rest assured that with both languages, you’ll get good community support. If you have an issue or query (related to either of the languages), you are likely to get a quick solution online.
Ease of Learning
Kotlin requires much more cognitive effort than Java. This makes Java easier to learn and implement (though you’ll need to write more code for it.).
If you are an abstract thinker, learning Kotlin might not be an issue for you. However, in normal situations, it is safe to say that Java is easier to learn.
In the case of clean builds with the Gradle daemon, tests suggest Java is 17% faster in the compilation than Kotlin. With the Gradle daemon warmed up, the results show Java being 13% faster than Kotlin.
However, clean builds are a rarity in the coding world. Most developers work with incremental builds, and the compilation speed results for different types of incremental builds were as follows...
(After the Gradle daemon has been warmed up with two or three runs)
- With no change - Java (4.6 sec), Kotlin (4.5 sec)
- Change in a file not used by another user - Java (7 sec), Kotlin (6.1 sec)
- Change in a file that is imported by other files in the project - Java (7.1 sec), Kotlin (6 sec)
With those results, it is clear that while Java compiles ‘clean builds’ faster, Kotlin is quicker in the case of incremental builds.
Kotlin vs. Java: The Final Verdict
After having compared Java and Kotlin on several important paraments, we have now come to a final conclusion. Veteran users of Java might feel that switching from a familiar language to another makes little sense. And even for beginners, Kotlin has a steeper learning curve.
However, Kotlin offers two major advantages that are likely to make businesses want to make the switch.
- Kotlin significantly reduced app development timelines.
- Kotlin also reduces the chances of app crashes.
So now, businesses see a direct benefit in using Kotlin. Even if businesses hire an Android development company, they will prefer to go with Kotlin rather than Java — and this means that to be competitive in the market, developers need to take the extra efforts to learn Kotlin.
Thus, we can say that Java’s best days are behind us — Kotlin is the language of the future.
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