JavaScript vs C++: Differences and Similarities

JavaScript vs C++ Summary

JavaScript is made for the web, interpreted, and high-level. Its code typically only runs in browsers. C++ is extremely fast, compiled, mid-level, and statically typed. It serves as the backbone for many programs, operating systems, and other languages.

JavaScript and C++ are two very different, yet popular languages. However, they are both used extensively by professional programmers. They both have wide applications, are used around the world, and listed as some of the best languages to learn. So how do they stack up against each other? Let’s go over each individually, then compare the two languages.

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JavaScript

JavaScript was built for the web, and was initially created to “make web pages alive.” It came into appearance in 1995 via Netscape. It is a high-level, interpreted, scripting language. This means JavaScript doesn’t have a compilation step; it’s turned into virtual machine code on the spot at runtime, or, in this case, when the webpage loads. 

JavaScript has curly-bracket syntax, dynamic typing, and first-class functions. It also isn’t made to be run outside of a browser, and although there are some powerful non-browser applications that use it, those applications are mostly web-based. 

In fact, JavaScript stands with HTML and CSS as one of the core technologies of the internet. It enables interactivity in web pages, and it’s the default language for web applications. 

It’s used on most websites by an enormous margin: as of last year, 95% of all websites used JavaScript. Google, Facebook, and Youtube all use JavaScript. It’s so popular that most web browsers have a built-in engine just to handle it.

C++

C++ wasn’t built for the web… it was built for everything. In 1979, a Danish computer scientist named Bjarne Stroustrup wanted to make an extension to C that would allow it to use classes. This seed has since expanded to become one of the most well known and used general-purpose languages. 

It’s an object-oriented, compiled, middle level programming language built with performance and efficiency in mind. Many of the implementations of C++, like Gnu and Clang, are open source projects.

C++ is used everywhere from AAA video games to space probes. It’s even used to write compilers for other languages; including many of the engines that interpret JavaScript. While many languages have a specific use case where they shine best, C++, along with its other C language cousins, often form the backbone for many programs and languages that let other languages shine. 

Comparing JavaScript vs C++

So while these languages are quite different, and used for different applications, we can still stack them against each other to help you decide whether you want to learn JavaScript or C++. 

C++ vs JavaScript: Speed and Reliability

JavaScript is a higher-level language than C++, which is considered mid-level. This means that JavaScript is closer to a human language than C++, which is closer to ones and zeros. This means that JavaScript is able to do more with one line than C++ can, and JavaScript code is typically much shorter than C++

C++ has something JavaScript doesn’t: setup. If you’re coding in C++ you’re coding at mid-level, which means that less of the road is paved for you. If you want to make something for anything other than Windows, you’ll have more work on your hands.

While there is quite a lot of pre-existing code for C++, it’s not always promised that you will find the integration you’re looking for and that you won’t have to code something custom from the ground up to fit your application. JavaScript has a lot of cushioning around it, almost everything has a browser, and all modern browsers run JavaScript. 

C++ is also statically typed. This means you have to declare every type of variable while coding. JavaScript, on the other hand, is dynamically typed, which means the variables can change type at runtime. You don’t have to worry as much about whether something is a string or an integer in JavaScript, and therefore can type it a little quicker than you can C++.

It needs to be mentioned that C++ is a compiled language (and, ironically, a compiler language). This means that after you type your code you’ll have to compile it before it can run. This can take anywhere from a few seconds to an hour, depending on the length and complexity of your code. And you have to do this every time you make a change for troubleshooting or bug testing.

JavaScript is not weighed down by any compiler, it runs when you press play. Now, this isn’t necessarily a fair comparison, as JavaScript code is usually much shorter than the sometimes massive C++ programs that take so long to compile; but it’s still relevant. 

JavaScript vs C++: Syntax

JavaScript is a multi-paradigm language. It’s designed to support event-driven, functional, and imperative programming styles. It also has all of the APIs it needs for working with text, arrays, dates, and regular expressions. However, it doesn’t include any kind of input or output, like storage or graphics, these are all handled by the engine that runs it. 

C++ is rigid; it allows for a lot less leeway. C++ is object-oriented. It looks like old guard programming—curly braces and all—and has less forgiveness (read: no forgiveness) for missing a semicolon. It has objects, classes, methods, and instance variables. 

C++ vs JavaScript: Performance

For performance, in the sense of how quickly a compiled program can run, there is absolutely no competition. C++ is ten or more times faster than JavaScript across the board. There is no argument which is faster. In fact, a lot of the time when you compare two languages it’s going to be the C language with faster compile time.

This result is because C++ is mid-level and compiled. It’s already closer to machine code, and then it’s compiled to machine code, ready to run. JavaScript is an interpreted code. The thing you had to wait for before your C++ code was ready is the thing JavaScript does in the moment at runtime.

More than that, as a high-level language, JavaScript is easier to type, but more work for the interpreter at runtime. So while you can type up a program in JavaScript much quicker than C++, JavaScript code runs much slower. 

Something important to note about performance is that for JavaScript, it’s OK to be a little slower. JavaScript isn’t designed for heavy calculations in a restricted environment like C++ is. You won’t be programming any moon landers in JavaScript.

JavaScript is used for interactivity on web pages, not plotting a course to Jupiter or trying to emulate artificial intelligence. So a little delay isn’t a big deal if you were to use C++ for the same application as JavaScript. 

C++ vs JavaScript: Application

Both languages are used for wildly different things. JavaScript is for web and C++ is generally for everything else. However, they do overlap in a couple of places. One of those places is at the back end (or ‘server side’), where the data that you touch at the front end of a web page is processed on a server. 

JavaScript can form the backend with Node.js and Express.js, all part of a web stack from front end to backend. This is useful because usually the front end is written in JavaScript; so having the backend written in JavaScript makes sense. It’s easier to integrate and there are fewer problems along the way. Plus, it comes with all the modern bells and whistles offered by today’s web development stacks.

However, many backends have high resource requirements. They handle tens of thousands of requests at the same time. In these cases having a faster, more efficient, language like C++ is a boon, as fewer resources are required to handle all of these threads. C++ is compact and predictable and has lower resource requirements than JavaScript.

The other place they overlap is in game design. Modern AAA games sit at the bleeding edge of game technology, and most of them are programmed in C++. This is because these games have very complex calculations that have to be completed at a very rapid pace, especially for online games where a fraction of a second could make a difference.

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C++ is fast and efficient, it does a good job making these fast yet complicated calculations without consuming too much of your already strained hardware. 

JavaScript is the opposite. It’s easy to type and to learn, but by comparison it’s slow and limited in its features. JavaScript is only really meant for browsers, so most of the games one would make with JavaScript would be 2D games aimed for browsers. You can make 3D games with JavaScript, but you would be bending it out of shape to do something that’s already a well supported and established norm for C++. 

JavaScript vs. C++: Community

While C++ is much older than JavaScript, they have both been around and have been highly used for over 20 years. They have community everywhere.

They both have huge libraries and code examples. If you run into a problem, someone else has been there, and if you need an integration there’s a good chance it’s been built.

However, if we are comparing the two languages, C++ has more application and has been around longer, so it does have a bigger pool of people behind it. Either way, they are both so well supported there’s a good chance you wouldn’t notice the difference. 

Last Word

Both of these languages have unique properties and particular strengths and weaknesses, so picking one comes down to knowing which tool you need. 

Do you need something fast? Something widely supported for a desktop program, rocket launch sequence, or video game? C++ has your back. 

If you need flexible, web-supported, and easy to write and debug front end programs for the web, then JavaScript should be at the top of the list by a mile. Neither choice is wrong, they’re just different.