Private Members and Privileged Methods in Constructors and Objects

gistfile1.js

function Animal() {
  var name = 'Lion';
  
  // privileged method
  this.getName = function() {
    return name;
  };
}

var lion = new Animal();
console.log(lion.getName() === 'Lion');
console.log(lion.name === void 0);

// Object literals
var obj;

(function() {
  var name = 'bob lob law';
  
  obj = {
    getName: function() {
      return name;
    }
  };
})();

console.log(obj.getName() === 'bob lob law');

var altObj = (function() {
  var name = 'gob bluth';
  
  return {
    getName: function() {
      return name;
    }
  };
})();

console.log(altObj.getName() === 'gob bluth');

// Private members in the prototype property object for better performance

function Device() {
  var name = 'Nintendo Wii';
  
  this.getName = function() {
    return name;
  };
}

Device.prototype = (function() {
  var type = 'console';
  
  return {
    getType: function() {
      return type;
    }
  };
})();

var wii = new Device();
console.log(wii.getName() === 'Nintendo Wii');
console.log(wii.getType() === 'console');