javascript - Ok, we can have private identifiers in javascript, but what about protected ones?

Question

Simple as that, can we emulate the "protected" visibility in Javascript somehow?

Answer 1

Do this:

/* Note: Do not break/touch this object */
...code...

Or a bit of google found this on the first page:

http://blog.blanquera.com/2009/03/javascript-protected-methods-and.html

Answer 2

Sure you can. Here's another example.

Answer 3

What could that possibly mean? You don't have classes.

I suppose you could analyze caller to determine whether it meets some set of criteria for being permitted to call a method. This will be hideously inefficient and your criteria will always be spoofable.

Answer 4

这里有一个有趣的模式值得一提：JavaScript 构造函数可以返回任何对象（不一定是this）。可以创建一个构造函数，它返回一个代理对象，其中包含对“真实”实例对象的“真实”方法的代理方法。这听起来可能很复杂，但事实并非如此；这是一个代码片段：

var MyClass = function() {
    var instanceObj = this;
    var proxyObj = {
        myPublicMethod: function() {
            return instanceObj.myPublicMethod.apply(instanceObj, arguments);
        }
    }
    return proxyObj;
};
MyClass.prototype = {
    _myPrivateMethod: function() {
        ...
    },
    myPublicMethod: function() {
        ...
    }
};

好处是代理创建可以自动化，如果我们定义一个命名受保护方法的约定。我创建了一个这样做的小库：http: //idya.github.com/oolib/