Quiz Questions/JS

What are some of the advantages/disadvantages of writing JavaScript code in a language that compiles to JavaScript?


Some examples of languages that compile to JavaScript include CoffeeScript, Elm, ClojureScript, PureScript, and TypeScript.


  • Fixes some of the longstanding problems in JavaScript and discourages JavaScript anti-patterns.
  • Enables you to write shorter code, by providing some syntactic sugar on top of JavaScript, which ES5 lacks, but ES2015 is awesome.
  • Static types are awesome (in the case of TypeScript) for large projects that need to be maintained over time.


  • Require a build/compile process as browsers only run JavaScript and your code will need to be compiled into JavaScript before being served to browsers.
  • Debugging can be a pain if your source maps do not map nicely to your pre-compiled source.
  • Most developers are not familiar with these languages and will need to learn it. There's a ramp up cost involved for your team if you use it for your projects.
  • Smaller community (depends on the language), which means resources, tutorials, libraries, and tooling would be harder to find.
  • IDE/editor support might be lacking.
  • These languages will always be behind the latest JavaScript standard.
  • Developers should be cognizant of what their code is being compiled to — because that is what would actually be running, and that is what matters in the end.

Practically, ES2015 has vastly improved JavaScript and made it much nicer to write. There's more not really a need to use CoffeeScript these days. Instead, TypeScript is the preferred choice because of the added typesafety and improved developer experience it brings.