Today, JavaScript is not just a programming language, but rather a platform, which offers many advantages over other platforms:
It's the only language that enjoys native support in web browsers.
It's the only universal language that allows
building web apps with just one programming language; all other languages (like Java and C#) can only be used on the back-end and need to be combined with front-end JavaScript, so developers need to master at least two programming languages.
executing the same code (e.g., for constraint validation) on the back-end and the front-end.
It's the only language that allows dynamic distribution, that is, executing the same code (e.g., for business computations) either in the back-end or the front-end, depending on run-time conditions such as the available front-end resources.
It combines object-oriented with functional programming.
Its dynamism allows various forms of meta-programming, which means it enables developers to program their own programming concepts, like classes and enumerations.