ArticlesEngineeringkotlin features

Kotlin, Google’s new programming language, comes with a range of functionality. This post looks at the Kotlin features that help make developers’ lives easier.

Not only does Kotlin solve real-world problems developers face, it also ensures interoperability with Java. The versatility of Kotlin cannot be ignored, which is reason enough to make it the developer’s choice of the hour. Furthermore, developers consider Kotlin to be a safe and concise programming language.

Here are the Kotlin features that can help mobile developers build superior apps.




1. Efficiency


kotlin features


The Kotlin programming language is not only easy to learn, it is also effective in the way that it codes your application. Developers won’t need to spend a lot of time grasping this language. The syntax is intuitive and lean.

One of the most attractive Kotlin features for developers is that it reduces code length. Compared to Java, you can say the same things with less lines. In fact, the coding is approximately 20% less than Java. With this reduced length, you have better chances at improving quality and operations. Kotlin basically makes coding efficient and testing near perfect.



2. Extension Functions


As the name “extension function” suggests, this allows you to add extra features to your existing component, which makes it easy for you to add simple yet impressive features. This is perfect for calculations as well as for appending strings.

Let’s explore this with an example. Suppose you want to extend a class with new functionality. What would you do? Well, in most programming languages, you would drive a new class, right?

But that’s not the case with Kotlin. You can use extension functions here.

In simple terms, extension functions allow you to extend functionality without changing the major part of the code. The question is, where can you use it? Well, It works perfect in calculations as well as in appending strings.

Here’s how you can define extension functions in Kotlin.

Suppose you need to cut down the first and the last character of the string. In Java, you need to write the same boilerplate code again and again, but with the use of Kotlin, you can create an extension of the String class.

Here is an example:


fun  String.removeFirstLastChar(): String = this.substring(1, this.length – 1)


This snippet will cut down the first and last character of String.

How to use it:


val  myString = “Hello World”

val result = myString.removeFirstLastChar()


We can use this function to extend any class and create an extension for it.

In short, with extension function, you can extend any class. Yes, any class. Even if you don’t have access to the code.



3. Massive Interoperability


public class  Customer {

private String name;

public Customer(String s){
name = s;

public String getName() {
return name;

public void setName(String name) { = name;


This is an excellent example of Java interoperability. You can run Java codes on Kotlin and vice versa. You just need to add the Java class above to your Kotlin project.

The two languages co-exist, which makes developers’ lives easier and more productive. You can easily compile your single project in both languages with the help of the interoperability function, which allows you to switch the programming language without switching the codes.

Kotlin is a language that is 100% interoperable. If you want to access a Kotlin method from a Java class or vice versa, you can do it without any extra parameters.

Here is a simple example:

Suppose you have a BaseActivity created in Kotlin, which contains the function printLog that simply prints the message.


fun printLog(msg : String){ //Kotlin Function


What if your MainActivity is in Java? If you want to print the message, then just write the message and pass the argument (String message).


private void main(){ //Accessing Kotlin Function from Java
printLog(msg:“Print this message.”);


This will automatically print the message in the logs.



4. Reducing Crashes at Runtime


Nullablevar name: String? = null
Non-null-var name: String = “abc”


In Kotlin, you can easily identify the NullPointerException while compiling your project. This ensures every variable works as a non-null, thus reducing the number of crashes at run-time. If you want to hold onto a null value, just append a question mark as the end of the variable type, as shown above.



5. Smart Cast Function


val  n:Any = “Hello”

when (n) {
is String -> n.length
is Int ->


This is the ultimate function from a developer’s perspective. It effectively reduces the application’s speed, thus improving its performance. The smart cast function is known to identify the type of function. It will perform all operations that have been coded for a particular type, thus improving code efficiency. Let’s say you have identified a string. With the smart cast function, you can copy, count the length, and perform other functions on the string type.



6. Safe and Reliable


As mentioned earlier, one of the strongest Kotlin features is that it is relatively safe. Avoiding errors such as “NullPointException” is easy with Null Safe function. This function even allows you to avoid use for nullable types. You can automatically remove mistakes and simplify your code for debugging and operations.



7. Low Cost of Adoption


A major reason businesses favor Kotlin over other programming languages is the no or low cost of adoption associated with it. It is open source, so you don’t need to invest money on license. Secondly, relative to other programming languages, Kotlin is pretty easy to learn for developers.



Summing Up Kotlin Features


Kotlin is the future of Android app development. It is a highly reliable, flexible, and safe language. With minimal cost involved and increased efficiency promised by the language, using Kotlin could boost profitability and improve business. Furthermore, it will not just reduce errors but also crashes at runtime, thus making debugging reliable.



About the Author:

Yuvrajsinh Vaghela is a Business Growth Strategist and a part-time technical writer at Space-O Technologies, a GESIA award-winner Android app development company in India. As he works with experienced Android app developers, he frequently shares technical articles related to Android app development. When he is not working on a technical article, he explores tools that can help entrepreneurs to grow their business.



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