object.创建和参考属性

Question

您如何处理在孩子之间共享原型参考属性的问题？是否有众所周知的模式（其他然后重新定义构造函数内部的属性）来解决此问题？这根本是一个问题，还是我缺少的原型继承的东西？

示例：

var dog = 
{
    name: "no-name",
    paws: ["front-right", "front-left", "back-right", "back-left"]
};
var rex = Object.create(dog);
rex.name = "Rex";
var bingo = Object.create(dog);
bingo.name = "Bingo";
bingo.paws.pop(); //Bingo is just like a dog, but has lost a paw in a tragic accident
console.log(bingo.paws); //["front-right", "front-left", "back-right"]
console.log(rex.paws); //Rex lost a paw too! ["front-right", "front-left", "back-right"]

更新：

在研究了原型链接后，在我看来，这种范式中的"自然"编程方式是扩展对象，而不是在将它们用作"类"的意义上依靠构造函数。我在博客上看到的示例（似乎也与道格拉斯·克罗克福德（Douglas Crockford）的Object.create一致）或多或少类似：

var Dog = 
{
    name: "no-name",
    paws: ["front-right", "front-left", "back-right", "back-left"],
    bark: function() { alert("Bark!!"); }
};
//No constructor acting like a "class"
var BigDog = Object.create(Dog);
BigDog.bark = function() { alert("WOLF!!!"); };
var thor = Object.create(BigDog);
thor.name = "Thor";
thor.bark();

构造函数是在新实例上复制或创建新数组的唯一方法吗？Object.create"不完整"的模式？

感谢您的答案！

Answer 1

众所周知，对象的原型是包含构成该对象的基本属性的对象。与所有对象一样，该原型对象是将名称映射到值的映射。JavaScript中的数组（和对象）始终是通过参考传递的，因此，当对Object.ert.create在原型上调用时 - 仅将数组的引用复制到新对象中。正如Thez在他的评论中所说的那样，您可以做这样的事情：

function Dog(){
    this.paws = ['front-right', 'front-left', 'back-right', 'back-left'];
}
Dog.prototype = {
    name: 'no-name',
    paws: null
};

所以我们现在可以创建我们的对象：

var rex = new Dog();
rex.name = 'Rex';
var bingo = new Dog();
bingo.name = 'Bingo';
bingo.paws.pop();

Answer 2

您应该查看模块模式

闭合可以使用，以便您的狗可以分开

var dog = function(){
 //private
 var name = "no-name";
 var paws = ["front-right", "front-left", "back-right", "back-left"];
 //public
 function getName(){
  return name;
 }
 function setName(newName){
  name = newName;
 }
 function getPaws(){
  return paws;
 }
 function pawPain(){
  paws.pop();
 }
 //expose
 return{
  pawPain: pawPain,
  getPaws: getPaws,
  getName: getName,
  setName: setName
 };
};

现在您可以使用它来制作新狗

var rex = new dog();    
var bingo = new dog();
rex.pawPain();
console.log(bingo.getPaws());

Answer 3

http://jsfiddle.net/svasp/

只需要一个构造函数。每个版本都包含自己的对象副本。

    function dog(name) {
        this.name = "no-name",
        this.paws = ["front-right", "front-left", "back-right", "back-left"]
    } 
    var rex = new dog();
    rex.name = "Rex";
    var bingo = new dog();
    bingo.name = "Bingo";
    bingo.paws.pop(); //Bingo is just like a dog, but has lost a paw in a tragic accident
    console.log(bingo.paws); //["front-right", "front-left", "back-right"]
    console.log(rex.paws); //Rex lost a paw too! ["front-right", "front-left", "back-right"]​