Kotlin versus Java | Developer.com



Java and Kotlin are two extraordinarily well-liked 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 is no such thing as a motive why you can’t use each, which we’ll talk about in additional element under. On this programming tutorial, we’ll talk about the variations between Kotlin and Java, and their use circumstances. We’ll embody code examples, the place acceptable, for demonstration functions.

What’s Kotlin?

Kotlin tutorials

Kotlin is a more moderen programming language that you’ll have heard of in relation to Java. It was launched by the developer instrument maker, JetBrains, in 2011, making the language just a bit over a decade outdated. 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 totally suitable with present 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 help for useful programming than Java supplies, presently.

You’ll be able to study extra about Kotlin in our tutorial: Introduction to Kotlin.

What’s Java?
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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, cellular 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, partially 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 help OOP options like inheritance, polymorphism, courses, objects, and encapsulation. Nonetheless, 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’s not the case with primitive information varieties.

You’ll be able to study extra about Java in our tutorial: What are the Advantages of Java?

What are the Variations Between Java and Kotlin?

Under we’ll spotlight among the most vital variations between Java and Kotlin, which ought to enable you to resolve which language you wish to pursue or write your challenge in – for those who 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 acknowledged, 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 take a look at a easy “Good day, World!” program written in each languages:

Instance code for “Good day,World!” written in Java:

public class HelloWorldExample {
    public static void essential(String[] args) {
        System.out.println("Good day, World!");

The above code, when ran in an built-in improvement atmosphere (IDE) or code editor, produces the output:

Good day, World!

Right here is similar “Good day, World!” programing written in Kotlin:

enjoyable essential(args: Array) {
    println("Good day, World!")

As soon as extra, operating this code creates the identical output as our Java code:

Good day, World!

Previewing the 2 examples, we are able to see that the Kotlin model is far shorter and extra accommodates much less code. Kotlin’s essential operate doesn’t require a category, and the kind of the arguments will get robotically inferred, saving us a bit of labor. Extrapolate that right into a a lot bigger program, and you may simply see the advantages of Kotlin’s syntax.

For one more instance, we are able to take a look at the way you create courses in Java versus the way you create courses in Kotlin:

Right here is a few instance code displaying how you can create a category in Java:

public class Human {
    personal String identify;
    personal int age;
    public Human(String identify, int age) {
        this.identify = identify;
        this.age = age;
    public String getName() {
        return identify;
    public void setName(String identify) {
        this.identify = identify;
    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: identify (a String worth) and age (an int or integer worth).

To attain the identical factor in Kotlin, we might use the next code, which reveals how you can create a category in Kotlin:

class Human(var identify: String, var age: Int)

As soon as extra, Kotlin requires far fewer strains 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 aren’t technically a worth in the identical manner 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 applications that may result in crashes or sudden habits 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 identify = null;

The above code, when run, ends in a null pointer exception at runtime as a result of the worth of the variable identify 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 identify: String? = null

Right here, the ? image infers that the identify variable can be null, and the size property is simply accessed if the worth of identify is not null. Coding on this manner protects applications from null pointer exceptions at compile time.

You’ll be able to study extra about Java and null values in our tutorial: How one can Deal with Null Values in Java.

Kind Inference

Java is a statically typed language; this implies Java builders should specify a variables kind after they declare it. This may change into tedious and burdensome, particularly when utilizing varieties.

Kotlin, nonetheless, makes use of kind inference, which means the compiler is ready to robotically infer the info kind of a variable primarily based on its worth. As soon as extra, this makes code simpler to put in writing, extra environment friendly, readable, and fewer vulnerable to bugs.

Practical Programming

Kotlin is understood for its help for useful programming, whereas Java solely started supporting useful programming in Java 8. Kotlin incorporates useful programming options similar to lambdas, higher-order features, and lets programmers deal with features as first-class residents.


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 of 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 features 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 eager 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 20 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 nicely, and it has loved lots 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 bettering and builders anticipate it’s going to change into at the very least as performant as Java, if no more so, within the close to future.

Neighborhood Assist and Studying Sources

Not surprisingly, Java boasts a somewhat giant, thriving, and veteran group, with tons of assets obtainable to builders. These assets 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 desperate to lend their information and assist your study and troubleshoot code. And a few even at no cost!

Kotlin’s group, as we might anticipate, is smaller than Java’s, however it’s rising at a speedy tempo. Kotlin is having fun with a progress spurt and persevering with recognition in recent times, and has even been adopted by many giant tech corporations, similar 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 carry 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 group help, stability, and safety. Regardless of this (or perhaps due to this), Java’s syntax could be verbose and it lacks among the fashionable language options that Kotlin presents, together with null security and concise syntax.

Kotlin, for its half, does provide a concise syntax, higher help for useful programming, and nice null security options. Kotlin can also be 100% interoperable with Java, making it an awesome choice for corporations that wish to migrate present Java codebases to a extra fashionable, environment friendly programming language.

In the end, selecting between Java and Kotlin will rely in your particular wants and preferences. In case your challenge requires excessive efficiency, stability, and a big codebase, backed up by loads of framework choices, libraries and instruments, Java would be the more sensible choice. In case you are engaged on a software program challenge or utility that requires fashionable language options and help for useful programming, Kotlin is a good choice.

Irrespective of which you select, each Java and Kotlin are robust programming languages which can be broadly used for software program improvement. As a programmer, it’s at all times a good move to maintain up-to-date with the newest programming languages and instruments and to decide on the language that’s finest fitted to the duty at hand – even when meaning a number of languages.

Learn: Finest Practices for Java Builders