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Learn moreThe Kotlin programming language has been a top-ranked developer preference for three years now, according to a Stack Overflow survey. It is officially supported by Google and is actively used in projects such as Jira and Adobe. Many developers of popular Android applications are switching to Kotlin, rewriting their products from other languages. Let's consider the advantages of this language, its unique features, and the income level of programmers working with it.
What is Kotlin
Kotlin is a modern programming language developed by JetBrains in 2011 as a more concise alternative to Java. The language is 40% more compact than its predecessor, significantly accelerating the development of the company's flagship product, the IntelliJ IDEA IDE. Fully compatible with Java and running on its Java virtual machine (JVM), Kotlin provides developers with a convenient and efficient tool for creating modern applications. It significantly reduces the amount of code needed, increasing productivity and simplifying project maintenance. Kotlin is an object-oriented programming language with a static typing system. This means that variable data types are determined at compile time, enabling early error detection and improving code reliability. Kotlin is designed to improve developer productivity by simplifying syntax and providing functionality such as extensible functions and lambda expressions. The language is fully compatible with Java, making it an ideal choice for developing applications for the Android platform and other areas where high performance and code security are required.
Object-oriented programming languages are languages in which all operations are performed with objects—structured blocks of code that allow you to store and process multiple values. An object can be any entity with a specific set of characteristics, for example, a character in an online game or a SpongeBob sticker in the Telegram messenger. All objects are created based on templates known as classes, which define their properties and methods. Using an object-oriented approach allows developers to create more flexible, scalable, and maintainable applications, making it an important aspect of modern programming.
Static typing assumes that the types of variables are determined by the developer before the program is executed. For example, if you declared a variable as an integer, attempting to put text into it will cause a compilation error. Although this may slow down the development process initially, static typing significantly improves the reliability of the code. It allows you to avoid many errors associated with mismatched data types, which in turn simplifies the maintenance and scaling of applications. Using static typing is especially useful in large projects, where the complexity of the code increases, and it is important to ensure its stability and predictability.
If you want to delve deeper into the topic of typing and its various types, we recommend reading one of our previous articles. It provides accessible information that will help you quickly understand this issue.
The roots of the international company JetBrains are in St. Petersburg. The programming language created by this company is named after an island in the Gulf of Finland. This name not only refers to the cultural context of the city, but also emphasizes the connection with the Java language, since both Java and Kotlin are names of islands.
What can be written in Kotlin
Kotlin is a universal programming language that can be used in all areas where Java is used. This includes backend development, web applications, desktop solutions, and many other tasks. As Andrey Breslav, the language's creator, emphasizes, "Kotlin is a language for all platforms." This phrase reflects the true nature of Kotlin, allowing developers to create applications on different devices and in various environments. Thanks to its compatibility with Java and modern tools, Kotlin provides developers with the flexibility and capabilities to effectively solve problems in a variety of areas.
Each programming language has its own specific area of application in which it is most actively used. Kotlin currently has two main niches: server-side and mobile development. However, this language is increasingly finding application in other areas, such as scientific research and data science. Given its versatility and capabilities, Kotlin is becoming an increasingly popular choice among developers.
Let's consider each area one by one.
Until 2017, Java remained the main programming language for Android application development. However, after this, Google announced the transition to Kotlin as the preferred language for its mobile operating system. Kotlin offers developers more modern and convenient tools, which allows them to create higher-quality and more efficient applications. This transition also opens up new opportunities for streamlining development processes and improving the user experience, making Kotlin an important choice for modern Android developers.
- partly due to a lengthy lawsuit with Oracle over the use of certain Java mechanics;
- partly because developers liked the new language, spontaneously began writing mobile apps in it and regularly pestered the corporation: “You will support Kotlin, right? Well, say it officially! It’s good!”
Today, 80% of the most popular apps on the Play Market are developed in the Kotlin programming language. This list includes such well-known apps as Netflix, Twitter, Reddit, and even developments from Google. Kotlin has established itself as an effective and modern tool for creating mobile applications, making it the number one choice for many developers.
Thanks to compatibility with the Java Virtual Machine (JVM), the Kotlin programming language can be run on any server that supports Java. This makes Kotlin popular for backend development, that is, the portion of software systems that runs on the server and is not accessible to users. Cloud services such as Jira, as well as some Adobe products, have already been implemented in Kotlin, confirming its effectiveness and popularity in the development of modern web applications. Using Kotlin to create backend solutions allows developers to build reliable and scalable systems, making it an excellent choice for businesses.
Server-side development is a key niche for the Kotlin team. Despite Kotlin's widespread popularity in mobile development, the JetBrains DevRel team focuses on the language's capabilities specifically in the context of server-side programming, completely ignoring mobile aspects. This underscores Kotlin's strategic focus as a powerful tool for building server-side applications, making it an important choice for developers seeking efficient and productive solutions in this area.
The frontend, or "facade" side of the web, is the interface with which users interact. It includes elements such as buttons, drop-down menus, and windows. The primary programming language for frontend development is JavaScript, which enables the creation of dynamic and interactive web applications. Importantly, an effective frontend not only improves user experience but also contributes to a website's visibility in search engines. Therefore, frontend optimization for SEO is a key aspect that helps attract more users and improve search rankings.
Kotlin can be compiled to JavaScript, making it suitable for developing the frontend portion of web applications. This means that Kotlin can be used to implement both business logic and the user interface, creating fully-fledged web applications. Using Kotlin for the frontend ensures high performance and a modern approach to development, making it an excellent choice for developers.
We need to develop a mobile app for scooter rentals that will function effectively on both Apple devices and Android smartphones. The app must provide a user-friendly interface, fast loading speed, and stable operation across various phone models. It's important to consider all the technical features of both platforms to ensure users can easily find, rent, and pay for scooters, as well as receive up-to-date information on available vehicles in real time. Cross-platform development is an approach in which code is written once and then adapted for various operating systems. This significantly simplifies the development process and reduces time to market. The Kotlin programming language implements Multiplatform technology, which allows developers to create cross-platform applications. This technology is already actively used by many companies, including Yandex. Multiplatform provides flexible application development capabilities, ensuring high performance and ease of support. If you work in data science, you are familiar with Jupyter Notebook. This development environment allows you to execute code piecemeal and immediately see results. It is widely used in the fields of machine learning, statistics, and data visualization. Initially, Jupyter only supported Python, Ruby, and R, but now it supports Kotlin. By incorporating several libraries, you can create voice assistants such as Siri or Alice. Jupyter Notebook is a powerful tool for developing and testing algorithms, making it indispensable for data analysis professionals.
Kotlin is becoming increasingly popular among scientists, including physicists and mathematicians. The KMath library, which offers advanced mathematical functions and provides integration with TensorFlow, is currently being actively developed. This makes Kotlin an attractive choice for scientific research and computing, allowing specialists to effectively use modern tools for data analysis and mathematical modeling.
Kotlin vs. Java
Java and Kotlin are interoperable programming languages, making them popular among developers. Both languages are statically typed, support object-oriented programming, and run on the Java Virtual Machine (JVM). In certain development environments, it is possible to mix the functions and classes of these languages. However, there are important differences between them that can influence the choice of language for a specific project. Let's take a closer look at these differences.
When Java first appeared, it stood out for its simplicity and conciseness compared to C and C++. While Java's syntax remains clear and logical, by today's standards it can seem redundant and outdated. This is because Java focuses on backward compatibility, which is especially important for the enterprise sector, where the "coffee" language is still the standard. Backward compatibility allows companies to seamlessly update their systems and applications, making Java a reliable choice for business development.
The creators of Kotlin initially focused on code compactness. The fewer unnecessary elements, the easier it is for the programmer to work, and the development process becomes faster. As a result, in Kotlin, one concept can be expressed with one line of code, while in Java it would require eighteen lines. This difference is especially noticeable when comparing data classes in both languages. Kotlin offers a more concise and readable syntax, making it a preferred choice for developers seeking efficient coding.
Creating a Person class in Java is an important step in object-oriented programming. The Person class can be used to represent a person with various attributes, such as name, age, and gender.
First, you need to define the basic properties of the class. In Java, this can be done using class fields. For example, create fields for name, age, and gender. Then add a constructor that allows you to initialize these fields when creating a new object.
Also, it is useful to implement accessor methods (getters and setters) to manage field values. This will improve encapsulation and provide control over access to the object's data.
An example implementation of the Person class might look like this:
public class Person {
private String name;
private int age;
private String gender;
public Person(String name, int age, String gender) {
this.name = name;
this.age = age;
this.gender = gender;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
@Override
public String toString() {
return «Person{name='» + name + «‘, age=» + age + «, gender='» + gender + «‘}»;
}
}
Thus, creating a Person class in Java allows you to effectively manage data about a person, provides the ability to extend functionality and improves the structure of the program.
Declaring a class in Kotlin is an important aspect of its syntax and structure. In Kotlin, a class is declared using the "class" keyword, followed by the class name. You can also specify its properties and methods. Classes in Kotlin support inheritance, allowing you to create class hierarchies and improve code organization. Additionally, Kotlin offers capabilities for creating data classes, which simplify data storage and manipulation. The use of interfaces and abstract classes in Kotlin also expands the functionality and flexibility of programming, allowing developers to create more complex and easier-to-use structures.
The odds seem to be in Java's favor. This programming language is better adapted to working with the JVM, allowing applications to compile 15-20% faster than Kotlin. However, it's worth noting the importance of incremental compilation, which allows rebuilding only those sections of the project where changes have been made, rather than the entire project. This significantly speeds up the development process and increases programmer productivity, making Java an even more attractive choice for creating high-performance applications.
By connecting a special plugin to Kotlin, you can achieve compilation that is faster than Java. Thus, in this regard, we can talk about parity between the languages.
Java, along with Python and C, is one of the most popular programming languages in the world. In the TIOBE ranking for March 2022, Java ranks third, while Kotlin is in 31st place. However, it is worth noting that Kotlin is a new language, and its scope of application is constantly expanding. At the same time, Java is increasingly used to maintain existing projects rather than developing new solutions. This highlights the need to understand Java's historical context and the relevance of learning Kotlin for today's developers.
Programming safety refers to how a programming language helps a developer avoid errors. In statically typed languages like Java and Kotlin, the compiler monitors data type compatibility, preventing errors that occur when trying to mix incompatible types, such as a string and a number. This ensures more reliable code and simplifies debugging, allowing programmers to focus on the application logic rather than troubleshooting data type errors.
Kotlin provides many built-in features that simplify working with data types. One such feature is smart casting. It allows the language to automatically convert variables to a single type depending on the code context. This improves readability and simplifies the development process, allowing developers to focus on the application logic instead of worrying about explicit type casts. Using smart cast significantly optimizes code and reduces the likelihood of errors related to incorrect type use.
Other killer features of Kotlin
Kotlin offers a number of unique features that provide advantages in speed, safety, and performance. Firstly, static typing allows errors to be detected at compile time, which minimizes the number of potential bugs in the code. Secondly, support for functional programming helps create cleaner and more understandable code, which speeds up the development process and simplifies further project maintenance. It is also worth noting that Kotlin is fully compatible with Java, which allows developers to easily integrate it into existing projects and use existing libraries. In addition, a modern build system and performance optimization make Kotlin an excellent choice for developing mobile applications on the Android platform, ensuring high speed and responsiveness of applications.
Coroutines are a powerful tool for implementing parallelism in programming, allowing you to execute several operations simultaneously. If necessary, execution of one function can be suspended, preserving all its data, allowing execution of another function to be switched. This makes coroutines particularly useful for asynchronous programming, when multiple tasks need to be handled without blocking program execution. Coroutines improve the performance and responsiveness of applications by efficiently managing resources and execution time.
Creating an electronic diary for students is a relevant task that allows them to easily access their grades and homework. In such an application, students will be able to quickly view their current academic progress and track their assignments. An electronic diary will be a convenient tool for organizing the learning process, increasing student engagement and responsibility. Users will be able to not only see their grades but also receive notifications about new assignments, making the learning process more transparent and effective.
Loading data from the server sequentially can significantly slow down the app's loading time. To improve loading speed, it's a good idea to move unnecessary data, such as news, into a coroutine. This will pause its loading until the main interface has finished loading. This approach not only speeds up app launch but also provides a smoother user experience.
Coroutins provide efficient priority management in programs. This mechanism is similar to multithreading, but uses significantly fewer processor resources. This makes coroutines especially valuable in mobile development, where limited resources require performance optimization. Using coroutines allows developers to create more responsive and efficient applications, a key aspect of modern programming.
In programming languages that support object-oriented programming (OOP), all objects are created based on special templates known as classes. Classes define the fundamental characteristics and functionality of objects, determining their structure and behavior. This allows developers to create more organized and modular code, making software applications easier to maintain and extend.
During software development, there may be a need to extend a class, adding new parameters and functionality. In Kotlin, this problem is solved using extension functions, which allow you to elegantly modify classes. Using extension functions makes code more readable and maintainable, and also helps improve its structure. This is especially useful in cases where you need to add new properties or methods to existing classes without changing their source code.
Java developers often encounter the Null Pointer Exception. This error occurs during program execution when code attempts to access an object whose value is null. Null Pointer Exception can cause application crashes, so it is important to know how to avoid this problem. To minimize the risk of this exception, it is recommended to always check variables for null before using them, as well as use annotations that help statically analyze your code. Effective memory management and the use of constructs such as Optional can also significantly reduce the likelihood of a Null Pointer Exception in your Java application.
In large and complex projects, the process of finding error lines can be long and exhausting. However, in the Kotlin programming language, this problem is practically eliminated, since all variables are non-null by default. The compiler stops building the project immediately if it detects that the value of any variable is null. This prevents the error from appearing in the finished application, which significantly simplifies debugging and increases the reliability of the code. Using Kotlin promotes more efficient development, minimizing the time spent finding and fixing errors.
In our articles, we've covered in detail what exceptions are in Java and how to handle them effectively. We've discussed the main types of exceptions, how to handle them, and methods that can help developers deal with errors in their code. Understanding exception handling is an important aspect of Java programming because it allows you to create more robust and reliable applications.
What about the money
Kotlin is a programming language that is not yet widely used among developers. As a result, companies are willing to offer competitive salaries even for entry-level specialists. According to Stack Overflow, Kotlin ranks in the middle of the pack among high-paying programming languages, surpassing languages like JavaScript, SQL, PHP, and Java, but behind more popular languages like Perl, Go, and Scala. This creates excellent opportunities for career advancement and attracting talented developers to Kotlin.
Kotlin occupies a leading position in the Russian development market in terms of salaries. According to Habr Careers, the average salary for Kotlin specialists increased by 13% in 2021, reaching 180,000 rubles per month, compared to 160,000 rubles the previous year. This confirms the growing demand for developers who know this programming language, which makes Kotlin one of the most attractive areas for IT specialists in Russia.
Open in Moscow and St. Petersburg There are 2,100 job openings for specialists proficient in Kotlin. Most companies, approximately 75%, are looking for Android developers, while the remaining positions are for backend developers and data analysts. Salaries for entry-level specialists range from 30,000 to 100,000 rubles, while mid-level developers can expect to earn 120,000 to 250,000 rubles. Senior developers and team leads can earn up to 500,000 rubles per month. Qualified personnel in the field of Kotlin development remain in demand, which opens up broad prospects for career growth and professional development.
If you have a high level of English proficiency, you should consider working remotely for an American or European company. Kotlin developers are in demand, and their work is competitively paid - from $4,000 at the initial stage of a career. Remote work for international companies opens new horizons and opportunities for professional growth in IT.
We recommend first gaining experience in the Russian market, as it is extremely difficult for beginners without practice to find work abroad.
Where to start?
Kotlin is a concise and modern programming language that is simple and easy to use. It is free of unnecessary formal operations, unnecessary type checks, and other aspects that can irritate developers. Thanks to its clear and understandable syntactic structure, Kotlin is easy to learn even for beginners, but to get a successful start, you need to immerse yourself in the language's fundamentals and concepts.
To learn Kotlin, you should start with the official documentation on the JetBrains website. Although it is only available in English, a semi-official translation created by the community is available. It's also recommended to read the book "Kotlin in Action" by the language's creators, Dmitry Zhemerov and Svetlana Isakova, which provides a detailed and accessible explanation of the fundamentals of Kotlin programming. Additionally, JetBrains Academy offers a free course on Kotlin fundamentals, but it's also in English.
Google offers free Kotlin tutorials that will be useful for both beginners and programmers already familiar with Java. However, it's worth noting that these materials are intended for users with at least a basic knowledge of English, as translations into Russian and other languages are not publicly available.
Programmers have an effective way to speed up the learning process and make it more engaging. They should choose and implement their own pet project while they're still learning. This could be a simple program, such as a task manager, a news parser, or a Telegram bot. The main advantage of a pet project is the ability to implement a complex abstraction and immediately monitor its operation. Furthermore, a successful project can be included in your portfolio, significantly increasing your chances of future employment. Creating your own project not only helps solidify your acquired knowledge but also develops the skills necessary for a professional programming career.
At the initial stage, the Kotlin Playground online compiler is an excellent tool for practice. It allows you to easily test your code and experiment with the Kotlin language. When you're ready to move on to developing a full-fledged app, you'll need a more powerful tool, such as Google's Android Studio or JetBrains' IntelliJ IDEA. These development environments offer advanced capabilities for creating and debugging apps, significantly simplifying the development process.
If you're looking to start a career in Android development, consider the "Android Developer" course from Skillbox. In 12 months, you'll master Kotlin programming, learn how to design user interfaces, and create apps that correspond to a Junior-level developer. Upon completion of the course, you will receive a diploma that will allow you to demonstrate your skills, for example, by developing your own social network for your portfolio.
