在我看来，你们大多数人都给出了getter和setter的例子，而不是一个构造函数，即http://en.wikipedia.org/wiki/Constructor_(object-oriented_programming)。

lunch -dan更接近，但是这个例子在jsFiddle中不起作用。

这个例子创建了一个私有构造函数，该函数只在创建对象期间运行。

var color = 'black';

function Box()
{
   // private property
   var color = '';

   // private constructor 
   var __construct = function() {
       alert("Object Created.");
       color = 'green';
   }()

   // getter
   this.getColor = function() {
       return color;
   }

   // setter
   this.setColor = function(data) {
       color = data;
   }

}

var b = new Box();

alert(b.getColor()); // should be green

b.setColor('orange');

alert(b.getColor()); // should be orange

alert(color); // should be black

如果你想要分配公共属性，那么构造函数可以这样定义:

var color = 'black';

function Box()
{
   // public property
   this.color = '';

   // private constructor 
   var __construct = function(that) {
       alert("Object Created.");
       that.color = 'green';
   }(this)

   // getter
   this.getColor = function() {
       return this.color;
   }

   // setter
   this.setColor = function(color) {
       this.color = color;
   }

}

var b = new Box();

alert(b.getColor()); // should be green

b.setColor('orange'); 

alert(b.getColor()); // should be orange

alert(color); // should be black

这种模式对我很有帮助。使用这种模式，你在单独的文件中创建类，“根据需要”将它们加载到整个应用程序中。

// Namespace
// (Creating new if not instantiated yet, otherwise, use existing and just add to it)
var myApp = myApp || {};

// "Package" 
// Similar to how you would establish a package in other languages
(function() {

// "Class"
var MyClass = function(params) {
    this.initialize(params);
}

    // "Private Static" vars 
    //    - Only accessible to functions in this class.
    //    - Doesn't get wiped out when we create a new instance.
    var countInstances = 0;
    var allInstances = [];

    // "Private Static" functions 
    //    - Same as above, but it's a function accessible 
    //      only to other functions in this class.
    function doSomething(){
    }

    // "Public Static" vars
    //    - Everyone has access.
    //    - Doesn't get wiped out when we create a new instance.
    MyClass.counter = 0;

    // "Public Static" functions
    //    - Same as above, but anyone can call this "static method".
    //    - Kinda like a singleton class situation.
    MyClass.foobar = function(){
    }

    // Public properties and methods are built into the "prototype"
    //    - This is how each instance can become unique unto itself.
    //    - Establishing "p" as "local" (Static Private) variable 
    //      simply so we don't have to keep typing "MyClass.prototype" 
    //      for each property and function.
var p = MyClass.prototype;

    // "Public" vars
    p.id = null;
    p.firstname = null;
    p.lastname = null;

    // "Private" vars
    //    - Only used by "this" instance.
    //    - There isn't "true" privacy for each 
    //      instance so we have to fake it. 
    //    - By tradition, we indicate "privacy"  
    //      by prefixing it with an underscore. 
    //    - So technically, anyone can access, but we simply 
    //      don't tell anyone about it (e.g. in your API)
    //      so no one knows about it :)
    p._foo = null;

    p.initialize = function(params){
        this.id = MyClass.counter++;
        this.firstname = params.firstname;
        this.lastname = params.lastname;
        MyClass.counter++;
        countInstances++;
        allInstances.push(this);
    }

    p.doAlert = function(theMessage){
        alert(this.firstname + " " + this.lastname + " said: " + theMessage + ". My id:" + this.id + ".  Total People:" + countInstances + ". First Person:" + allInstances[0].firstname + " " + allInstances[0].lastname);
    }


// Assign class to app
myApp.MyClass = MyClass;

// Close the "Package"
}());

// Usage example:
var bob = new myApp.MyClass({   firstname   :   "bob",
                                lastname    :   "er"
                            });

bob.doAlert("hello there");

我想我会发布我用javascript闭包做的事情，因为还没有人使用闭包。

var user = function(id) {
  // private properties & methods goes here.
  var someValue;
  function doSomething(data) {
    someValue = data;
  };

  // constructor goes here.
  if (!id) return null;

  // public properties & methods goes here.
  return {
    id: id,
    method: function(params) {
      doSomething(params);
    }
  };
};

欢迎对此解决方案提出意见和建议。：）

也许它变得简单了一点，但以下是我在2017年想出的:

class obj {
  constructor(in_shape, in_color){
    this.shape = in_shape;
    this.color = in_color;
  }

  getInfo(){
    return this.shape + ' and ' + this.color;
  }
  setShape(in_shape){
    this.shape = in_shape;
  }
  setColor(in_color){
    this.color = in_color;
  }
}

在使用上面的类，我有以下:

var newobj = new obj('square', 'blue');

//Here, we expect to see 'square and blue'
console.log(newobj.getInfo()); 

newobj.setColor('white');
newobj.setShape('sphere');

//Since we've set new color and shape, we expect the following: 'sphere and white'
console.log(newobj.getInfo());

如您所见，构造函数接受两个参数，我们设置对象的属性。我们还通过使用setter函数改变对象的颜色和形状，并证明在这些改变之后调用getInfo()时它的变化仍然存在。

有点晚了，但我希望这能帮到你。我已经用摩卡单元测试了这个功能，效果很好。

只是为了提供一些变化。ds。Oop是一种在javascript中使用构造函数声明类的好方法。它支持所有可能的继承类型(包括一种甚至c#都不支持的类型)以及很好的接口。

var Color = ds.make.class({
    type: 'Color',
    constructor: function (r,g,b) { 
        this.r = r;                     /* now r,g, and b are available to   */
        this.g = g;                     /* other methods in the Color class  */
        this.b = b;                     
    }
});
var red = new Color(255,0,0);   // using the new keyword to instantiate the class

这是一个构造函数:

function MyClass() {}

当你这样做时

var myObj = new MyClass();

MyClass被执行，并返回该类的一个新对象。