JavaScript is a scripting language mainly used in interactive web pages but also for servers2 with the use (for example) of Node.js3. It is an object-oriented to prototype language, that is to say that the bases of the language and its main interfaces are provided by objects that are not class instances, but which are each equipped with constructors to create their properties, and in particular a prototyping property that makes it possible to create personalized heir objects. In addition, the functions are first class objects. The language supports the object paradigm, imperative and functional. JavaScript is the language with the largest ecosystem thanks to its dependency manager npm, with about 500,000 packages in August 20174. (wikipedia)