Recs.
Updated
SpecsUpdate
Pros
Pro No installation required
If you run a web browser you already have JavaScript installed and can get started right away. Modern browsers such as Chrome also have very powerful programming consoles built into them.
Aside from the browser console, you can also use online Javascript playgrounds such as JS Bin and JS Fiddle. Even from a tablet.
Pro Great ecosystem
JavaScript has one of the largest programming ecosystems, as shown by the being the most popular language for projects on GitHub. As there are so many projects written in JavaScript there are lots of libraries available to build off of and many of them are written to be easy to use and integrate into other projects.
There are also lots of resources available for learning JavaScript. Other than traditional tutorials, language learning sites such as Codecademy have JavaScript courses. The Mozilla Developer Database also serves as a great resource for learning about the standard libraries built into JavaScript.
Cons
Con Complex
JavaScript has a long litany of warts and gotchas. JavaScript will bite you if you're just a wee bit careless. You have to exercise a great deal of caution and awareness. You either have to know the entire 545-page ES6 spec to avoid them all, or use a linter to help restrict you from using the bad parts (and you still have to be familiar with the language), but beginners don't know these things. (Linters are also prone to time-wasting false positives.) This is a significant cognitive burden on even the experienced programmer (as if coding wasn’t hard enough already), but try learning to program in the first place on top of all of this and you'll understand that JavaScript is a terrible choice for the beginner.
Con The `null` and `undefined` objects aren't really objects
Therefore, attempts to call methods on them will fail. This is especially frustrating since these are often returned instead of throwing exceptions. So a failure may appear far away from the actual cause, which makes bugs very hard to find.
Con Each browser has its own quirks when executing the same code in some cases
Beginner programmers often make the mistake of coding something, seeing it works in the browser they tested it in, and then scratching their heads when it doesn't work in another browser. Ideally you'd want a language that works consistently across all platforms in order to be able to focus more on the programming and less on the underlying environment. It just takes time away from learning and forces you to spend time figuring out why this worked in browser X but not browser Y.
Con Does not teach you about data types
Since JavaScript is a weakly typed language, you don't have to learn about data types if you start using JavaScript as your first language. Data types being one of the most important concepts in programming. This will also cause trouble in the long run when you will have to (inevitably) learn and work with a strongly or statically typed language because you will be forced to learn the type system from scratch.
Con Easy to accidentally use globals
If you forget a var
or new
, you can clobber the global scope. For tiny scripts (JavaScript's original use case) globals are great, but for larger applications globals are generally regarded as a Bad Thing. This is because changes to one small part of a program can randomly break things anywhere else. These kinds of bugs are notoriously hard to find.