If you have ever thought about starting a career in IT, you have probably wondered about the most popular programming languages to learn in 2023. There are several hundred languages in the programming world today, and choosing the one you'll devote substantial time and effort to is quite difficult. In this article, you will discover what Java is, its characteristics and advantages for the newcomer in IT, as well as the fields it applies to and its prospects for the future.
What is Java?
Java is a universal programming language that is currently used to develop many well-known applications, programs, websites, and most of the operating systems for modern smartphones: Netflix, eBay, Amazon, Android, etc.
It is one of the best-known and most popular languages. Approximately nine million people now work in it, and Java applications run on seven billion devices. TIOBE's February 2023 rating ranks Java as fourth in the world in terms of usage.
Although Java is a rather old language with almost 30 years of history, it has been popular since its introduction in 1995 and became a leader by the end of the 2010s, along with Python. There are many different areas of development in which it operates, and it continues to evolve.
Where is Java used?
Almost everything can be written in Java, and the scope of the language is very wide. Here are just a few examples of programs in Java:
Take an Android phone. Absolutely all apps for it are written in Java. It is the main development language for Android. Java is also one of the languages that were used to write Android itself.
Server applications in the financial services industry
Java is widely used in the financial sector. Many global investment banks like Goldman Sachs, Citigroup, Barclays, Standard Chartered, and others use Java to write front-end and back-end office electronic systems, regulatory and confirmation systems, data processing projects, and so on. These are the applications that banks use exclusively for internal purposes, but not for customers. Examples may include applications that enable transactions to be made or trade transactions to be recorded.
Java is also used to write many web applications: from e-commerce projects to large portals, from educational platforms to government resources. Web applications include email clients, social networks, search engines, online shops, online business software, etc.
Big data technologies also use Java. For example, data scientists create, teach, and test neural networks using the language. Although Java does not dominate this field today ― as, for example, Scala or R do, it has every chance to take the lead, as data science is constantly evolving.
The cloud is a computing resource that is provided to the internet user as an online service. Companies are moving everything from data storage and individual services to entire IT infrastructures to cloud platforms. And Java has become the most popular programming language for business development in the cloud. Last year, the independent Cloud Foundry Foundation (CFF) conducted a survey among 600 IT professionals and found that 58% of respondents use Java to develop business applications in the cloud.
Stories of successful games written in Java include RuneScape and Minecraft. The initial version of the game was created in just six days. Minecraft is the second best-selling game in the world. Java is also regularly used in VR/AR technology, as well as CGI in movies ― for example, in The Avengers.
Not only developers need Java. Testers and software automation specialists also use it. It’s also suitable for genetic research and physics. With Java, you can simulate physical laws and processes. For example, in the Jenetics library, you can create genetic and evolutionary algorithms.
Java is one of the core technologies in such projects as Google, Meta (Facebook), and Telegram. But other languages are used in place of it because large companies always use several tools for large projects — this increases reliability, usability, and speed of use. Let's look at the case of a combination of languages, taking the example of entering a password on a website:
- You visit the website of a bank and press the login button. You see a logo, text, and a form for entering your login and password — that is HTML, a browser markup language.
- So you entered the accesses correctly and pressed "Enter". The browser asks the server if the username and password were correct and then launches you into your account — that is Java.
Java's key features
Java is an object-oriented programming language
Java follows the model of object-oriented programming. It’s an approach that views a program as a set of interacting objects, each with its own properties and behavior and belonging to a certain class. Programmers do not work specifically with objects but write classes — which are recipes for these objects.
Let's look at the notion of "programmer" as a class. A specific developer named John is an object belonging to the class "programmer". Salary, job duties, education, and position in the company are properties that all objects of the "programmer" class have, including John. Different objects have different properties: John's salary and duties will be different from those of Hugh — another developer.
In the above example, we consider the programmer as a class, but at the same time, it’s a subclass of an even more general class — work or HR department — which consists of objects such as employee, section, etc.
Thus, for a lot of real-world and business cases thinking of things as "objects" is natural and useful. These objects can also map well to data in databases. However, it's not about the amount of data, but more the convenience of thinking of it this way.
Normally, a Windows program cannot run on macOS; you have to rewrite a lot of it. A Java program, on the other hand, can, because it has a special program that executes the code — the Java Virtual Machine (JVM). You write the program code once — it works with any platform or operating system, from smartcards to smart home applications.
An example is Facebook Messenger, which you can install on any operating system — macOS, Windows, or Linux — without any changes to the application's internal code. That is, the JVM works like an adapter that picks up the right connection method.
Here it is important to understand the term typification. It is the division of variables into different types ― for example, int (integer), flow (decimal number), string (a string of text), and bool (true/false). The type of variable is determined by the data you enter into the code. Imagine opening your fridge. You might see tomatoes, yogurt, and sausages — these are variables. There is a vegetable, a dairy product, and a meat product, respectively.
Java has static and strict typing. This means that when you enter any variable you have to define its type, and the programming language itself can tell you if there is an error somewhere. For example, if you get sausages and want to make a salad with them, Java will give you an error, because sausages should not be in the salad. However, you must first explain to Java that the tomatoes should be treated as vegetables and that the sausages are meat ― not baked goods.
Java is an algorithmic language
Programming languages are divided into description declarative languages and algorithmic imperative languages. The former is only for describing data for different types of applications. These languages are considered a necessary load for imperative languages. These, of course, can also describe data but are mainly for creating large and complex programs that describe actions, i.e. algorithms.
Imagine that you find a recipe for a dish. In the first part, you see a list of ingredients, their quantities, and some additional characteristics. This would be the declarative language or the language of the description. It includes, for example, HTML and CSS. The next part tells you what you have to do to make the finished dish, i.e. the algorithm itself. This would be an imperative or algorithmic programming language.
Java syntax is very sensitive. For example, it’s important not to confuse capital and small letters. Class names will begin with capital letters and function names will begin with small ones. In addition, the name of a program file must match the name of a class exactly, including the case. For example, if the class name is "FirstClassName", the file must be called "FirstClassName.java".
Of course, if a Java program is written incorrectly for syntaxis, the compiler will display an error message, pointing to the file or line in the file where it thinks the error occurred and the mistake can be corrected. The compiler is a program that converts the source code into a low-level language suitable for execution by the Java Machine. Moreover, searching for errors at compile time makes the work much easier, because these errors can be corrected immediately, and the program itself will make fewer errors at run-time in the future.
Memory management mechanisms
Garbage collection is the process of restoring runtime memory by deleting unused objects. In Java, this process happens automatically. That is, the programmer does not need to manually analyze which files they do or don’t need every time. On the other hand, the developer cannot always control this process. An iPhone works on a similar principle when it unloads long unused apps.
Java is a rather common language ― a great number of developers use it, and the solution to almost any problem that may arise using Java has already been figured out by someone. Thanks to thousands of libraries and forums, it is possible to find a ready-made solution to almost any issue. GitHub, for example, has open-source projects and documentation, and the Stack Overflow forum offers help from the community.
The most popular libraries and frameworks for Java
One of the key features of Java is that it has mature and useful libraries and frameworks. They allow programmers to streamline workflows and deliver specific functionality using pre-built, reusable pieces of code. Here are the most popular ones:
- Apache Commons — comprises 43 modular libraries covering domains such as collections, math, classes, database, caching, and so on.
- Google Guava — developed by a Google open-source library that reduces coding errors, simplifies standard coding methods, and improves performance by making code shorter and easier to read.
- Jackson — a suite of data processing libraries for Java.
- Mockito — the most widely used mocking library in Java.
- Spring — a framework for the development of web applications.
Competitors: how does Java differ from Python and C?
Java's main competitors in popularity are C and Python. However, it is impossible to say which programming language is better, as each is suitable for different tasks and situations. For example, Python is widely used for web applications, while C is predominantly used for writing operating systems.
Java combines the best of compiled and interpreted languages. What does this mean? A programming language is a language in which the programmer and the processor agree on how to execute commands. But the processor does not need to know all the languages, so the programmer needs to translate the command into a form the processor can understand. There are two ways to do this — interpretation and compilation.
Python is an interpreted language, so the processor needs a special interpreter program (translator) to understand it. Usually, the interpreter is rather slow. C is a compiled language, which means that it’s adapted to the processor in advance, and no translation is needed when the program is run. In other words, Python is a language that is easy to use and human-friendly but not computer-friendly, while C is the opposite.
So, Java is a compilable language with a syntax (commands) that is much simpler and easier for a human to understand than other such languages. There are a few more points of comparison between Java, Python, and C:
Java is generally faster than Python. But on rare occasions, small code in Python runs faster than in Java because it doesn't use a virtual machine. However, Java is slower than C because its syntax is easier for a computer to process and doesn't need extra translations.
The advantage of Java is that it is written once and runs on all platforms that use a Java Machine, a special program that executes the code. Python is a similar story, but a C program has to be rewritten for each hardware.
C contains functions that are considered difficult to enter into programming: manual memory allocation, direct pointer handling, and so on. Python is considered the easiest language to learn because of its simple syntax. Java for beginners is somewhere in the middle in terms of complexity.
Java code is much longer than that of Python. Where Python needs one line, Java takes five. However, C is much more complicated and awkward for a beginner than Java. Just look at the simplest program, "Hello, World", written in Python, Java, and C:
Statistics on salaries for Java developers
The average Java developer salary in the US today is $117,000 per year. Newcomers are paid slightly less — $99,705. At the same time, highly experienced specialists can earn up to $147,856.
A programmer's salary level depends on skills as well as the company's location. The highest salaries for Java developers are in West Virginia, New York, and California.
In addition, it’s important to note that it is advisable for Java developers to have additional skills, such as knowledge of related programming languages (Scala, Groovy), libraries (JHipster, Maven, Guava), programming environments (IntelliJ, Eclipse), code testing applications (JMeter, JaCoCo), and other tools. This will help further increase income.
The prospects for Java developers in the labor market are very bright. Demand always exceeds supply, both locally and globally. Therefore salaries are constantly rising and conditions are improving.
How to start learning Java
Programming in Java does not require special mathematical skills, but it is helpful to have algorithmic thinking, which is the ability to solve a given problem with the help of an algorithm. However, these skills can also be developed with constant practice, as can the ability to write Java itself. The more you practice, the sooner you will learn a new profession and find an interesting and well-paid job.
The basis is the same for everyone, and you can write both applications and the backend. However, you have to know your tools for each area, which are built with Java. For example, for Android, you need a thorough understanding of how the Virtual Machine works, and for the backend, you need to learn high-level frameworks ― Spring and Java EE.
A portfolio can have a bigger impact on your employment than a certificate. During your studies at TripleTen Bootcamp, you will be able to compile a professional portfolio. The TripleTen Career Centre exists for this purpose and will help you get it right and present it to your future employer.
So why choose Java?
Java is one of the three most popular programming languages. You can develop a program of any complexity in Java ― an online shop, banking applications, and even artificial intelligence. It is used in a wide variety of fields, from e-commerce sites to Android applications, from games to desktop software. All this makes Java a great language for programming beginners.
An essential part of learning Java and continually developing as a programmer is learning additional tools ― libraries, frameworks, etc. Remember that Java itself is only the tip of the iceberg.
There are huge career and salary prospects for a Java developer. Once you have decided on the area in which you want to develop, you can expand your knowledge of development and learn Java-related languages. Anyway, regardless of your future goals, Java can handle a wide range of tasks and be very useful.
For those who want to quickly learn new skills and get into a new profession, TripleTen has prepared several courses, including Software Engineering Bootcamp. This is a comprehensive solution, where in addition to the theory you get a lot of practice and work on real cases. Completing these courses will vastly simplify your further development in Java.