是的，你可以像这样在类声明中定义构造函数:

class Rectangle {
  constructor(height, width) {
    this.height = height;
    this.width = width;
  }
}

下面是一个模板，我有时会在JavaScript中使用类似oop的行为。如您所见，您可以使用闭包模拟私有(静态和实例)成员。新的MyClass()将返回一个对象，该对象仅具有分配给这个对象和“类”的原型对象中的属性。

var MyClass = (function () {
    // private static
    var nextId = 1;

    // constructor
    var cls = function () {
        // private
        var id = nextId++;
        var name = 'Unknown';

        // public (this instance only)
        this.get_id = function () { return id; };

        this.get_name = function () { return name; };
        this.set_name = function (value) {
            if (typeof value != 'string')
                throw 'Name must be a string';
            if (value.length < 2 || value.length > 20)
                throw 'Name must be 2-20 characters long.';
            name = value;
        };
    };

    // public static
    cls.get_nextId = function () {
        return nextId;
    };

    // public (shared across instances)
    cls.prototype = {
        announce: function () {
            alert('Hi there! My id is ' + this.get_id() + ' and my name is "' + this.get_name() + '"!\r\n' +
                  'The next fellow\'s id will be ' + MyClass.get_nextId() + '!');
        }
    };

    return cls;
})();

有人问过我使用这种模式的继承问题，所以如下:

// It's a good idea to have a utility class to wire up inheritance.
function inherit(cls, superCls) {
    // We use an intermediary empty constructor to create an
    // inheritance chain, because using the super class' constructor
    // might have side effects.
    var construct = function () {};
    construct.prototype = superCls.prototype;
    cls.prototype = new construct;
    cls.prototype.constructor = cls;
    cls.super = superCls;
}

var MyChildClass = (function () {
    // constructor
    var cls = function (surName) {
        // Call super constructor on this instance (any arguments
        // to the constructor would go after "this" in call(…)).
        this.constructor.super.call(this);

        // Shadowing instance properties is a little bit less
        // intuitive, but can be done:
        var getName = this.get_name;

        // public (this instance only)
        this.get_name = function () {
            return getName.call(this) + ' ' + surName;
        };
    };
    inherit(cls, MyClass); // <-- important!

    return cls;
})();

还有一个例子:

var bob = new MyClass();
bob.set_name('Bob');
bob.announce(); // id is 1, name shows as "Bob"

var john = new MyChildClass('Doe');
john.set_name('John');
john.announce(); // id is 2, name shows as "John Doe"

alert(john instanceof MyClass); // true

正如您所看到的，类之间正确地交互(它们共享来自MyClass的静态id, announce方法使用正确的get_name方法，等等)。

需要注意的一点是需要对实例属性进行阴影处理。您实际上可以让继承函数遍历所有实例属性(使用hasOwnProperty)是函数，并自动魔术般地添加一个super_<方法名>属性。这将允许您调用This .super_get_name()，而不是将其存储在临时值中并使用call调用它。

对于原型上的方法，你不需要担心上面的问题，如果你想访问超类的原型方法，你可以调用this.constructor.super.prototype.methodName。如果你想让它不那么冗长，你当然可以添加便利属性。：）

使用上面Nick的示例，您可以使用return语句作为对象定义中的最后一条语句为不带参数的对象创建构造函数。返回你的构造函数，如下所示，它将在你每次创建对象时运行__construct中的代码:

function Box()
{
   var __construct = function() {
       alert("Object Created.");
       this.color = 'green';
   }

  this.color = '';

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

   __construct();
}

var b = new Box();

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。

例如:http://jsfiddle.net/FZ5nC/

试试这个模板:

<script>
//============================================================
// Register Namespace
//------------------------------------------------------------
var Name = Name||{};
Name.Space = Name.Space||{};

//============================================================
// Constructor - MUST BE AT TOP OF FILE
//------------------------------------------------------------
Name.Space.ClassName = function Name_Space_ClassName(){}

//============================================================
// Member Functions & Variables
//------------------------------------------------------------
Name.Space.ClassName.prototype = {
  v1: null
 ,v2: null
 ,f1: function Name_Space_ClassName_f1(){}
}

//============================================================
// Static Variables
//------------------------------------------------------------
Name.Space.ClassName.staticVar = 0;

//============================================================
// Static Functions
//------------------------------------------------------------
Name.Space.ClassName.staticFunc = function Name_Space_ClassName_staticFunc(){
}
</script>

如果你定义一个静态类，你必须调整你的命名空间:

<script>
//============================================================
// Register Namespace
//------------------------------------------------------------
var Shape = Shape||{};
Shape.Rectangle = Shape.Rectangle||{};
// In previous example, Rectangle was defined in the constructor.
</script>

示例类:

<script>
//============================================================
// Register Namespace
//------------------------------------------------------------
var Shape = Shape||{};

//============================================================
// Constructor - MUST BE AT TOP OF FILE
//------------------------------------------------------------
Shape.Rectangle = function Shape_Rectangle(width, height, color){
    this.Width = width;
    this.Height = height;
    this.Color = color;
}

//============================================================
// Member Functions & Variables
//------------------------------------------------------------
Shape.Rectangle.prototype = {
  Width: null
 ,Height: null
 ,Color: null
 ,Draw: function Shape_Rectangle_Draw(canvasId, x, y){
    var canvas = document.getElementById(canvasId);
    var context = canvas.getContext("2d");
    context.fillStyle = this.Color;
    context.fillRect(x, y, this.Width, this.Height);
 }
}

//============================================================
// Static Variables
//------------------------------------------------------------
Shape.Rectangle.Sides = 4;

//============================================================
// Static Functions
//------------------------------------------------------------
Shape.Rectangle.CreateSmallBlue = function Shape_Rectangle_CreateSmallBlue(){
    return new Shape.Rectangle(5,8,'#0000ff');
}
Shape.Rectangle.CreateBigRed = function Shape_Rectangle_CreateBigRed(){
    return new Shape.Rectangle(50,25,'#ff0000');
}
</script>

示例实例化:

<canvas id="painting" width="500" height="500"></canvas>
<script>
alert("A rectangle has "+Shape.Rectangle.Sides+" sides.");

var r1 = new Shape.Rectangle(16, 12, "#aa22cc");
r1.Draw("painting",0, 20);

var r2 = Shape.Rectangle.CreateSmallBlue();
r2.Draw("painting", 0, 0);

Shape.Rectangle.CreateBigRed().Draw("painting", 10, 0);
</script>

注意函数定义为A.B = function A_B()。这是为了使您的脚本更容易调试。打开Chrome的Inspect Element面板，运行这个脚本，并展开调试回溯:

<script>
//============================================================
// Register Namespace
//------------------------------------------------------------
var Fail = Fail||{};

//============================================================
// Static Functions
//------------------------------------------------------------
Fail.Test = function Fail_Test(){
    A.Func.That.Does.Not.Exist();
}

Fail.Test();
</script>

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。：）