Question

我有一个javascript对象克隆问题。我希望能够克隆已经从对象原型定义的对象方法改变的对象方法，或者在实例化之后添加到对象中。这可能吗？

这里的设置是我定义的javascript“类”，所以我可以编写特定于我的对象类的克隆方法。我只是想不出如何复制方法。

示例：

function myObject( name, att, dif ) {
    /* 'privileged' methods */
    this.attribute = function(newAtt) {  // just a getter-setter for the 'private' att member
        if(newAtt) { att = newAtt; }
        return att;
    }
    // 'public' members
    this.printName = name;
}

myObject.prototype.genericMethod = function() {
    // does what is usually needed for myObjects
}


/* Create an instance of myObject */
var object153 = new myObject( '153rd Object', 'ABC', 2 );
// object153 needs to vary from most instances of myObject:
object153.genericMethod = function() {
    // new code here specific to myObject instance object153
}
/* These instances become a collection of objects which I will use subsets of later. */


/* Now I need to clone a subset of myObjects, including object153 */
var copyOfObject153 = object153.clone();
// I want copyOfObject153 to have a genericMethod method, and I want it to be the one
// defined to be specific to object153 above.  How do I do that in my clone() method?
// The method really needs to still be called 'genericMethod', too.

Answer 1

在你的clone函数中，测试对象上的每个方法，看它是否等于对象构造函数原型上的相同方法。

if (obj[method] != obj.constructor.prototype[method])
    clone[method] = obj[method];

Answer 2

听起来你只想要一份浅色的副本。但请注意，实例之间共享对象，因为我们没有深度复制。

function clone(obj) {
   var newObj = new obj.constructor();
   for (var prop in obj) {
     newObj[prop] = obj[prop];
   }
   return newObj;
}
var cloned = clone(object153);

不同的语法是

myObj.prototype.clone = function() {
   var newObj = new this.constructor();
   for (var prop in this) {
     newObj[prop] = this[prop];
   }
   return newObj;
}
var cloned = object153.clone();

尝试一下，看看它是否适合你，仍然很难说出你在做什么。如果没有，解释原因，那么我可以更好地理解这个问题。

如何编写可以复制添加的对象方法的javascript克隆函数？

2 个答案: