Java and Kotlin are two extraordinarily fashionable programming languages within the software program improvement realm. Each languages have their very own set of execs and cons, and builders may discover themselves confronted with selecting one over the opposite, although, in fact, there isn’t a purpose why you can’t use each, which we are going to talk about in additional element under. On this programming tutorial, we are going to talk about the variations between Kotlin and Java, and their use instances. We’ll embody code examples, the place applicable, for demonstration functions.
What’s Kotlin?
Kotlin is a more moderen programming language that you’ll have heard of in relation to Java. It was launched by the developer software maker, JetBrains, in 2011, making the language just a bit over a decade previous. It’s an open-source programming language that runs on the Java Digital Machine (JVM), and was initially developed as a predecessor for Java. As such, Kotlin is absolutely appropriate with current Java codebases, which implies you’ll be able to combine and mingle your Kotlin and Java code collectively.
As a proposed successor to Java, Kotlin was designed to be extra environment friendly, concise, expressive, and safer than Java, and its builders additionally sought to supply higher assist for purposeful programming than Java offers, at the moment.
You may study extra about Kotlin in our tutorial: Introduction to Kotlin.
What’s Java?

Java, in the meantime, is an older programming language, having been launched to the developer world again in 1995 by Solar Microsystems. It’s generally used for growing enterprise purposes, cell apps for Android gadgets, and server-side programming – to call however a couple of.
Java is a strongly-typed language with an emphasis on code readability, maintainability, and portability. That is thanks, partly to its object-oriented options; many programmers consider Java is a full-fledged object-oriented programming (OOP) language, however this isn’t fairly true; it does assist OOP options like inheritance, polymorphism, lessons, objects, and encapsulation. Nevertheless, Java makes use of primitive and non-primitive information varieties, which remove it from being a real OOP language, as a result of in object oriented programming, information varieties are objects – that isn’t the case with primitive information varieties.
You may study extra about Java in our tutorial: What are the Advantages of Java?
What are the Variations Between Java and Kotlin?
Under we are going to spotlight a number of the most necessary variations between Java and Kotlin, which ought to assist you to determine which language you need to pursue or write your mission in – should you choose to not use each.
Syntax Variations Between Java and Kotlin
Most likely the largest distinction between Java and Kotlin lies of their syntax. As said, Kotlin syntax is extra concise and fewer verbose when in comparison with Java, by design. Kotlin depends on fewer semicolons, braces, and different sorts of boilerplate code, which, in flip, makes it a lot simpler to learn, troubleshoot, and write. To see how a lot less complicated Kotlin is than Java by way of syntax, let’s have a look at a easy “Whats up, World!” program written in each languages:
Instance code for “Whats up,World!” written in Java:
public class HelloWorldExample { public static void fundamental(String[] args) { System.out.println("Whats up, World!"); } }
The above code, when ran in an built-in improvement surroundings (IDE) or code editor, produces the output:
Whats up, World!
Right here is identical “Whats up, World!” programing written in Kotlin:
enjoyable fundamental(args: Array) { println("Whats up, World!") }
As soon as extra, operating this code creates the identical output as our Java code:
Whats up, World!
Previewing the 2 examples, we are able to see that the Kotlin model is far shorter and extra incorporates much less code. Kotlin’s fundamental operate doesn’t require a category, and the kind of the arguments will get routinely inferred, saving us a bit of labor. Extrapolate that right into a a lot bigger program, and you’ll simply see the advantages of Kotlin’s syntax.
For an additional instance, we are able to have a look at the way you create lessons in Java versus the way you create lessons in Kotlin:
Right here is a few instance code exhibiting tips on how to create a category in Java:
public class Human { non-public String title; non-public int age; public Human(String title, int age) { this.title = title; this.age = age; } public String getName() { return title; } public void setName(String title) { this.title = title; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } }
Within the above code instance, we create a category named Human and gave it two properties: title (a String worth) and age (an int or integer worth).
To realize the identical factor in Kotlin, we’d use the next code, which reveals tips on how to create a category in Kotlin:
class Human(var title: String, var age: Int)
As soon as extra, Kotlin requires far fewer traces of code to create a category when in comparison with Java.
Learn: Java versus Python
Null Security in Kotlin and Java
Null security is one other distinction we should always talk about when breaking down the variations between Kotlin and Java. NULL values may cause errors if builders don’t account for them, as they don’t seem to be technically a worth in the identical approach that 100 or abc are. To that finish, Kotlin handles null security higher than Java, as Kotlin has a built-in system for null security that stops null pointer exceptions at compile time.
Java, in the meantime, doesn’t have this characteristic, and thus, null pointer exceptions are a standard supply of bugs in Java packages that may result in crashes or surprising conduct at runtime. Kotlin’s null security characteristic avoids this and ensures that code is freed from null pointer exceptions, making codebases extra steady and fewer error-prone.
Right here is a few instance code demonstrating issues with Null values in Java:
String title = null; System.out.println(title.size());
The above code, when run, leads to a null pointer exception at runtime as a result of the worth of the variable title is assigned null.
In Kotlin, it’s not doable to assign a null worth to a variable until programmers explicitly point out the null utilizing the ? image, as proven right here:
var title: String? = null println(title?.size)
Right here, the ? image infers that the title variable can be null, and the size property is simply accessed if the worth of title is not null. Coding on this approach protects packages from null pointer exceptions at compile time.
You may study extra about Java and null values in our tutorial: Methods to Deal with Null Values in Java.
Kind Inference
Java is a statically typed language; this implies Java builders should specify a variables sort after they declare it. This may turn into tedious and burdensome, particularly when utilizing varieties.
Kotlin, nevertheless, makes use of sort inference, which means the compiler is ready to routinely infer the info sort of a variable primarily based on its worth. As soon as extra, this makes code simpler to jot down, extra environment friendly, readable, and fewer vulnerable to bugs.
Useful Programming
Kotlin is understood for its assist for purposeful programming, whereas Java solely started supporting purposeful programming in Java 8. Kotlin incorporates purposeful programming options equivalent to lambdas, higher-order capabilities, and lets programmers deal with capabilities as first-class residents.
Interoperability
In programming and software program improvement, the phrase interoperability refers to how two or extra languages work collectively. If a programming language can name one other programming language’s code, then it’s thought-about interoperable with that language. One highly effective characteristic of Kotlin is its interoperability with Java, which is smart, because it was constructed off the Java Digital Machine and helps the entire capabilities inside Java. Due to this, Kotlin can name Java code and Java, in flip, can name Kotlin code with none points. Due to this, migrating code from Java to Kotlin is a snap and builders desirous to make the transition don’t have to rewrite their total codebase from scratch.
Learn: High Instruments for Distant Builders
Efficiency and Stability
Java has been round since 1995 – over twenty years – and has a mature developer ecosystem, which features a important variety of libraries, frameworks, and instruments. Due to this, Java purposes carry out very properly, and it has loved loads of efficiency optimizations since its inception.
In fact, Kotlin is a reasonably new language, and, as such, it has not benefited from as many efficiency optimizations as Java has. Regardless of this, Kotlin’s efficiency has been steadily enhancing and builders anticipate it is going to turn into not less than as performant as Java, if no more so, within the close to future.
Neighborhood Assist and Studying Sources
Not surprisingly, Java boasts a somewhat massive, thriving, and veteran neighborhood, with tons of sources out there to builders. These sources come within the type of boards, blogs, and tutorials devoted to Java, in addition to, instruments, frameworks, and libraries – to not point out the various seasoned Java builders that exist, all desirous to lend their information and assist your study and troubleshoot code. And a few even free of charge!
Kotlin’s neighborhood, as we’d anticipate, is smaller than Java’s, however it’s rising at a fast tempo. Kotlin is having fun with a development spurt and persevering with reputation lately, and has even been adopted by many massive tech corporations, equivalent to Google, JetBrains, and Atlassian, the maker’s of Jira.
Remaining Ideas on Java versus Kotlin
To summarize our tutorial, Java and Kotlin each have their strengths and weaknesses by way of what they create to the desk for programmers. Java has been round for fairly a while and has a extra mature developer ecosystem, which makes it a strong, feature-rich language with glorious neighborhood assist, stability, and safety. Regardless of this (or possibly due to this), Java’s syntax will be verbose and it lacks a number of the fashionable language options that Kotlin gives, together with null security and concise syntax.
Kotlin, for its half, does provide a concise syntax, higher assist for purposeful programming, and nice null security options. Kotlin can be 100% interoperable with Java, making it an incredible possibility for corporations that need to migrate current Java codebases to a extra fashionable, environment friendly programming language.
Finally, selecting between Java and Kotlin will rely in your particular wants and preferences. In case your mission requires excessive efficiency, stability, and a big codebase, backed up by loads of framework choices, libraries and instruments, Java often is the better option. If you’re engaged on a software program mission or software that requires fashionable language options and assist for purposeful programming, Kotlin is a superb possibility.
Irrespective of which you select, each Java and Kotlin are robust programming languages which are extensively used for software program improvement. As a programmer, it’s all the time a good move to maintain up-to-date with the newest programming languages and instruments and to decide on the language that’s greatest fitted to the duty at hand – even when meaning a number of languages.