Mastering JavaScript Design Patterns - Second Edition

ECMAScript 2015 classes and modules

We've seen so far that it is perfectly possible to build classes and even modules in pre ECMAScript -2015 JavaScript. The syntax is, obviously, a bit more involved than in a language such as C# or Java. Fortunately ECMAScript-2015, brings support for some syntactic sugar for making classes:

class Castle extends Westeros.Structures.BaseStructure {
  constructor(name, allegience) {
    super(name);
    ...
  }
  Build() {
    ...
    super.Build();
  }
}

ECMAScript-2015 also brings a well thought out module system for JavaScript. There's also syntactic sugar for creating modules which looks like this:

module 'Westeros' {
  export function Rule(rulerName, house) {
    ...
    return "Long live " + rulerName + " of house " + house;
  }
}

As modules can ...