13 Best Practices of Kotlin for Android App Development

7 min readDec 27, 2023

As a free, pragmatic, and open-source coding language, Kotlin amalgamates object-oriented and functional features seamlessly. Designed for Java Virtual Machines (JVM) and Android, Kotlin was declared as the favored programming language for Android app development by Google on 07 May 2019.

What are some essential features of Kotlin coding language that every Kotlin developer must be aware of? Let’s take a sneak peek.

This language has better compact and clear syntax.
Has seamless data classes and functional programming
100% interoperable with Java
Extensions add more functionality
Simplifies the error-finding and debugging process
More precise code lines
It’s easy to adopt and start practicing Kotlin.

Now, What are the best practices in Kotlin? Look no further, as our blog provides you with the best tips.

Top Kotlin Tips for Android App Development

Well, the first straightforward tip would be — you must hire Android developers with expertise in Kotlin, who can use the best practices to make the development phase faster, providing intuitive and world class Android applications. Kotlin’s best tips add scalability, functionality, smooth usage, and improved speed. So, let’s see the best practices or tips of Kotlin while developing Android applications.

#1 Use Lazy Load to Save Memory and Time

Android application developers always focus on lowering load timing and memory usage in Android applications because of the restricted and shared resources of mobile devices. That’s why when you use lazy loading in Kotlin, this enhances the effort.

Lazy load supports variables to be loaded only in the accessing timing. This is also apparent for memory usage, as the variable gets loaded into the memory when used, lowering start-up time for Android mobile applications.

#2 Write Precise Code with Lambdas

Usually, Lambdas aligns with Android and shortens the code to make it more legible, reliable, flexible, and functional. However, Kotlin takes the entire advantage that Lambdas comes with and ensures one step ahead or cutting-edge solution. So, what does it mean?

Well, Kotlin eliminates the headache of developers managing Retrolambdas and making changes to the development phase. Together, these empowered Kotlin to support Lambdas, establishing it as a super cool functionality in Kotlin.

#3 Evaluate Nullable Components with ‘Let’

To null check on components, the ‘if not null’ feature structure is mostly used by Android developers. However, Kotlin can seamlessly and quickly put an end to this complicated branching logic through Kotlin’s ‘let’ extension functionality.

Let us remind you that the declared components or properties within it have no use outside it. Although this is accessible or usable for nested ‘lets’ or chaining a handful, it is nullable only, making it an observing function.

#4 Have Custom Setters and Getters

Getters and setters prefer a model structure in Kotlin. However, developers can prefer to get and set any specific field through custom or personalized behavior with the model structure. When you use a custom model for frameworks, such as the Parse SDK, the values that are collected or fetched are not local variables. They are cached and reclaimed in a custom method, such as JSON, simplifying the custom usage of getters and setters, which resembles the use of property access syntax on different models.

Besides, if you need to change to another data source from Parse, you only have to alter the code in one place, and the rest will be taken care of! Isn’t it exciting?

#5 Convert Code from Java to Kotlin

Another standout Kotlin’s best tip is the seamless conversion of the existing Java code to Kotlin, a transformation and precise coding language. The simplest method to do this is to access from the menu entry. Otherwise, you can follow another method; let us remind you that’s also a good and favorable practice. For that, just open the Main Activity.java file ➡ ️ and choose ‘convert Java file to Kotlin file.’ stick to this trick, search the action, and convert the code to Kotlin smoothly.

#6 Data Classes

Honestly, handling data classes for Android app development is never an easy and simple task, not to mention the huge amount of time it consumes and the exhaustion it includes. So, what’s the solution? Oh boy, fortunately, Kotlin is there to rescue us by providing native support for data classes. These classes are specially designed for storing and maintaining data effectively, enabling Android developers to save time and effort while developing robust Kotlin-powered Android apps.

Embracing auto-generated methods, such as getters, setters, equals (), hashCode (), copy (), and toString (), developers can seamlessly build complex objects and simplify the classes, eliminating the need to write extra code. In fact, you can prefer JSON or Gson parsing libraries alongside the data classes for building a default constructor with default values. This advanced approach allows developers to create killer and scalable applications than before.

#7 Easy Validation

With the built-in features of Kotlin, performing validation is smoother than ever, enabling dedicated Android developers to check whitespaces mainly. By the way, have you ever used TextUtils.isEmpty (someString) while performing validation in other programming languages? If yes, then, man, you know!

We assure you that Kotlin, on the other hand, supports in-built isNullorBlank and isNullorEmpty, eliminating the usage of the TextUtils class requirement. Now, if you prefer mainly space possibility, using isNullorEmpty can be the best solution for you and if you prefer that your end users mainly input spaces, preferring isNullorBlank would be wise.

#8 Collection Filter

Kotlin framework offers in-built mapping and collection filtering, enabling developers to execute robust collection operations in a precise and smooth way. Applying complex logic with these features, developers can easily filter out and adjust collection contents while using an API. Leveraging the filter function not only strengthens Kotlin code structure, marking it concise and readable but also makes it remove unwanted items from the collection.

As a result, it fastens the Android application development process while helping other Android developers to understand the app’s backend data. Besides, uncluttered methodology resembles the collection types of Swift and streams of Java coding languages.

Also Read — Kotlin vs. Java: Select the Best for Android App Development

#9 Have Object Expression and Declaration

Kotlin’s object expressions and declarations ensure an effective method for defining objects, eliminating the need to create another class. This, of course, is important in creating a singleton object or an unknown class for abstract classes or interfaces. Embracing object expression, Android developers can easily define objects without the need for boilerplate code.

Additionally, object declaration enables developers to declare a single-instance object’s wide access in the application regardless of the place. Leveraging these functionalities helps developers in optimizing the code while building a robust application with ease.

#10 Use Companion Object

Companion objects are nothing but single-base objects that have a class of variables and methods. Kotlin enables you to define a companion object within a class for storing its components and functions. This is significantly impactful in the creation of constants or factory properties and supports writing precise, smooth, clear, and organized code. Utilizing companion objects, dedicated Kotlin developers can prevent static utility classes and prefer to keep the functionality all in one place.

Additionally, companion objects are a great source to keep static access in the Kotlin programming language seamlessly. Even to make the code versatile, extend the functionality and property of both the companion object and the class.

#11 Seamless Optional Parameters

Kotlin enables functions to have optional parameters. This means it has the functionality to be called with a subset of its parameters only. This feature is significantly important in helping Android developers to make the code more precise, clear, and organized. Furthermore, it supports developers the flexibility to select the required parameters based on particular or different use cases.

Besides, default values for optional parameters enables developers to reduce the chances of creating several overloaded functions, which, of course, simplifies the code complexity, making it effective. These important tips can empower Kotlin developers to streamline the entire project while writing readable codes and develop killer Android applications.

#12 Focus on Global Constants

In Kotlin, global constants are something that’s not even declared from inside the class, enabling it to be easily and seamlessly available from any place in the application. To write organized and concise code, Android developers declare the most preferred values and components utilizing these global constants. Please note that these preferred values and components don’t even belong to any defined class.

Additionally, extension functionality helps Android developers extend the functionality of any pre-existing classes, making it easier for them to alter or edit the class. What does it do? It unlocks the smooth path to writing flexible and well-defined code, significantly improving Kotlin-based Android applications. .

#13 The Ultimate Mantra: Practice, Practice, and Practice

Last but not least, the ultimate mantra to excel in Kotlin is nothing but to practice, practice, and practice with dedication. No matter how many tips and tricks you follow without failure, it won’t be fruitful. Man, to become a pro in the Kotlin programming language, at least take the first step and start developing small projects with Kotlin code. And then slowly start handling medium, bigger, and important projects, having authority over the programming language.

Although it may take a lot of time for you to get accustomed to the Kotlin language, once you’re armed with Kotlin, believe us, you need not look back as a dedicated developer building seamless and stellar Android app development.

Start Right Away!

Are you willing to start building Android app with Kotlin? Let’s give you assurance that Kotlin is an easy and simple coding language to learn and practice. The above-mentioned tips and tricks are your golden ticket to enter into the world of Kotlin mastery. Make better use of those and start right away!

However, suppose you’re stuck or have less confidence. In that case, you can contact an Android app development service and hire dedicated Kotlin developers, saving you from building an app with a language that you’re unfamiliar with. We, Magicminds, are at your service with our dedicated developers with expertise in Android app development services who will help you build smooth, scalable, and seamless mobile apps, taking your business to the next level and fostering growth.