factories.js

/* A éviter */
function dataService () {
  var someValue = '';
  function save () { 
    /* */
  };
  function validate () { 
    /* */
  };

  return {
    save: save,
    someValue: someValue,
    validate: validate
  };
}

/* Recommander */
function dataService () {
  var someValue = '';
  var service = {
    save: save,
    someValue: someValue,
    validate: validate
  };
  return service;

  ////////////
  function save () { 
    /* */
  };

  function validate () { 
    /* */
  };
}