something.coffee

class @Hello
  constructor: ->
    @greeting = "hello"

  greet: =>
    console.log @greeting

  print_number: ->
    number = 3
    console.log "#{number} is a number"

something.es6

class Hello {
  constructor() {
    this.greeting = "hello";
  }

  greet() {
    return (() => {
      console.log(this.greeting);
    })();
  }

  printNumber() {
    var number = 3;
    console.log(`${number} is a number`);
  }
}