Syntax

JS2 Syntax

Object Oriented Features

Classes:

class Person {
  function initialize(first, last) {
    this.first = first;
    this.last  = last;
  }

  function name() {
    return this.first + ' ' + this.last; 
  }
}

class Employee extends Person {
  function initialize(first, last, title) {
    this.$super(first, last);
    this.title = title;
  }

  function name() {
    return this.$super() + ', ' + this.title;
  }
}

Modules/Mixins:

module Walkable {
  function walk() {
    console.log('walking'); 
  }
}

class Person {
  include Walkable;
}

Private block: Adding a private block creates a lexical scope that all methods (static or instance) have access to.

class Employees { private { var JOB_TYPES = [ 'admin', 'engineer', 'hr' ]; }

 function getJobType() {
   return JOB_TYPES[this.jobIdx];
 }

}

Syntactic Sugar

Foreach:

var words = [ 'hello', 'world' ];
foreach (var word in words) {
  console.log(word);
}

Shorthand functions:

// works for $1, $2 and $3
var say = #{ console.log($1) }; 
say("hello");

// with named arguments
var say = #(word) { console.log(word) };
say("hello");

Heredocs:

var str = <<END
  this is a string
END

Interpolated Strings:

var name    = "John Doe";
var message = %{Welcome #{name}};

JSML: JavaScript Markup Language

var template = <<END:jsml
  %div.hello = this.message
END

// returns html
template.result({ message: "hello" });

Interop with JS2 in plain Javascript

You can still leverage some of JS2's syntactic sugar in plain Javascript by using some of the class methods available to JS2 classes.

var NewClass = OldClass.extend({ newMethod: function () { return "hello" } });