Java vs C++ - Differences And When To Use Which

At first glance, it can seem that they have a lot in common. Java and C++ are object-oriented programming languages, both high-level and cross-platform. However, we can compare different aspects of the languages and pick the winner in certain areas.

Also, keep in mind that even though they are called general-purpose languages, they still have a limited usage range.

What is Java?

Java is a secure, fast, and powerful programming language that is widely used in the IT industry for software development. It's an object-oriented programming language, which means it is organized around data or objects rather than functions and logic.

Java is platform-independent, meaning we can run the same code on multiple platforms, depending on our operating system of choice. It's possible because of converting Java source code to the byte code file. Then, JVM (aka Java Virtual Machine) will load the byte code file and convert it into machine code. Lastly, after compilation using the Just-In-Time (JIT) compiler, JVM will execute the optimized code.

Where can you use Java?

Java language powers millions of apps and websites. It's commonly used by big software companies because it's secure and reliable. Below, you can find the most common use cases of Java.

• Web-development. Java is a well-known server-side programming language. However, Java can be successfully used both for the back-end and front-end in HTML.
• Android applications. Java is best suited for creating Android apps. Because it is platform-independent, Java apps can work on any platform.
• Desktop applications. It might seem that desktop applications are becoming extinct, however, there are still a lot of things that are not possible to do online.
• Big data. A lot of popular big data tools are written in Java. And a great advantage of it is that some leading big data tools are open-source for Java developers.
• Internet of Things (IoT). Utilities that people use are becoming smarter and smarter every year, and Java is the most popular programming language for developing them. Smart home appliances, cellular technologies, factory robots - Java is surrounding you everywhere!

What is C++?

It is a high-level, general-purpose programming language created as an extension of the C language. It’s most known for its efficiency, swift memory utilization and performance.

Unlike Java, to run code C++ uses only the compiler that converts the source code into machine code. The result is it’s faster than Java but also platform-dependent and has to be compiled on every platform.

One of the biggest advantages of C++ is that it is super scalable, which means it can be used to develop large and fast software. It also allows developers to have control over system resources and memory and manage large amounts of data.

The latest version (C++23) has object-oriented programming, functional and generic features. It also allows for low-level memory manipulation.

Where can you use it?

Although C++ is platform-dependent, unlike Java, it has vast application areas. C++ is mostly known for its efficiency, high speed, and dynamic memory utilization. The most common use cases of C++ include:

• Game development. You can’t underestimate the importance of performance in video games. Here comes C++ to help us with extended control over memory resources.
• Graphics rendering. Graphics rendering is a process that requires a lot of PC resources. C++ gives more flexibility here.
• Compilers. C++ compilers read programs and convert them into object code. Compilers are programs that work through command-line interfaces, also known as CLIs. When compilers convert your program's code into object code, it's merely translating it so the computer can execute it directly.
• Libraries. C++ supports direct system library calls, making it suitable for system-level programming. Some C++ libraries even can be used by Java applications.

Is Java as powerful as C++?

Although both languages have their advantages, the truth is, in the right hands, C++ is more performant.

Java also supports only single inheritance, while C++ supports multiple inheritance. Moreover, Java doesn't react to direct native system libraries calls, only Java Native Interface. C++ supports direct system library calls.

However, it's important to note that C++ has some major drawbacks. It’s more complex in development, has higher cost of maintenance, and increased risks.

How does C++ achieve that high productivity? Here are the key advantages:

• Supports both Pass by Value and Pass by Reference
• Has global scope
• Supports operator overloading
• It is both a procedural and an object-oriented programming language
• All object management is manual
• It is closer to the hardware

Why do people use Java instead of C++?

While C++ can be more performant, Java still has its advantages. Java programming language is still more flexible and controllable, and it's a popular choice for software development. Other benefits of using Java include the following:

• Java is more modern. Java's first release happened in 1996, while the first edition of C++ came out in 1985. This is why Java was developed considering the mistakes and difficulties of C++.
• No garbage collection in C++. One of the biggest problems that C++ is criticized for is memory management. Releasing used memory is fully a developer's responsibility, making it a huge vulnerability because of the human factor.
• Java is easier to learn. Java is meant to be more human-friendly for faster development.
• Performance speed. Even though C++ is considered to be more performant, Java competes well, and it is faster for most of the tasks.

Downsides of Java and C++

Nothing is perfect, so let’s discuss what difficulties developers face using these programming languages.

Java

• Java syntax is close to a native human language, however, someone would call Java too lengthy compared to other languages.
• Since Java is a high-level language, it has to use an interpreter to be compiled to bytecode. Unfortunately, this affects performance.
• Another performance issue can be automatic memory management, manual work is harder but gives more flexibility and control.

C++

• The complexity. Developing a program in C++ isn’t a piece of cake. Learning to use it right takes a lot of dedication and time.
• Manual memory management. Developers have to always keep in mind to release unused memory in time. There is no garbage collector to help.
• The factors mentioned above lead us to one more point. C++ can be quite vulnerable. Of course, it depends a lot on the knowledge and experience of a developer, but even the best can make mistakes, and a mistake in C++ can cost you a lot.

Which is better for the future: Java or C++?

Despite all the talks about these languages dying, the truth is - they both have their places in the future.

A lot of software has already been written in these languages. As with every software - it now requires maintenance. I can say that Java and C++ developers will still be needed for a long time.

But it’s not only legacy code that makes Java and C++ so popular. Thousands of applications are being developed every day in these programming languages. Both of them are being relentlessly maintained and improved. They consider new trends and cutting-edge technologies.

As long as it is so, the demand for developing applications in both languages will be high. Which one you’ll use will depend on the purpose and specifics of your product.