Question

在javascript中，子类可以访问＆amp;更改基类变量？如果没有，是否有办法创建特权变量？我知道你可以创建特权函数，但特权变量呢？

这是我的尝试：

  function BaseClass()
  {
     var privateMap = {"type": "BaseClass"};
  }

  function ChildClass()
  {
     // How can I access BaseClass's private variable privateMap?
     privateMap["type"] = "ChildClass";
  }

  ChildClass.prototype             = new BaseClass();
  ChildClass.prototype.constructor = ChildClass;

Answer 1

您必须在privateMap中公开BaseClass：

BaseClass.prototype.privateMap = {"type": "BaseClass"};

然后您可以在ChildClass中访问它：

BaseClass.prototype.privateMap["type"] = "ChildClass";

Answer 2

var Base = function() 
  {
    var privateMap = {"type":"Base"};

    this.changeMap = function(arg) {
        privateMap['type'] = arg;
        console.log('Changed Map to ' + privateMap['type'])
    }

}
var Child = new Base;

Child.changeMap('Child1')

console.log(Child.privateMap)//undefined

从子类中访问基类变量

2 个答案: