如何实现析构函数？ [英] How to implement a destructor?
问题描述
我正在寻找一种方法来实现析构函数作为
类的成员方法。
/ * BEGIN CODE * /
函数SomeClass（）{
this.constructor.numInstances ++;
this.destroy = function（）{
this.constructor.numInstances--;
/ *
需要在这里删除实例
* /
};
}
SomeClass.numInstances = 0;
sc = new SomeClass（）;
// SomeClass.numInstances = 1
sc.destroy（）;
// SomeClass.numInstances = 0且sc不再被引用
/ * END CODE * /
如果只涉及删除操作（如 - 删除sc - in
上面的例子），我不需要一个析构函数，但是因为
一个操作更多（减少实例的数量;并且那里
可能更多），而且我不想将完全销毁
进程委托给实例化对象的程序，我需要实现一个析构函数
作为会员方法。
任何帮助都将在此得到赞赏。
F.
Hi,
I''m looking for a way to implement a destructor as a member method of a
class.
/* BEGIN CODE */
function SomeClass() {
this.constructor.numInstances++;
this.destroy = function () {
this.constructor.numInstances--;
/*
Need someway here to delete the instance
*/
};
}
SomeClass.numInstances = 0;
sc = new SomeClass();
// SomeClass.numInstances = 1
sc.destroy();
// SomeClass.numInstances = 0 and sc is not referenced anymore
/* END CODE */
If there was only a delete operation involved (as in -- delete sc -- in
the above exemple) , I wouldn''t need a destructor, but since there is
one operation more (decrementing the number of instances; and there
could be more), and I do not want to delegate the full destruction
process to the procedure which instantiated the object, I need to
implement a destructor as a member method.
Any help would be appreciated on this.
F.
推荐答案
Fran？ois写道：
Fran?ois wrote:
我正在寻找一种方法来实现析构函数一个
类的成员方法。
Hi,
I''m looking for a way to implement a destructor as a member method of a
class.
为什么？ JavaScript中的删除与Java或C ++中的删除不同。
-
Ian Collins。
Why? delete in JavaScript isn''t the same as in Java or C++.
--
Ian Collins.
Ian，
我需要实现它以便我可以删除一个实例并在
同时提供一系列由破坏：
sc.destroy（） - >删除sc和 - >减少实例数
和 - >做一些其他动作（触发事件，弹出警报（
对象sc已被销毁）或其他一些动作，
破坏的所有部分过程）
我可以在课堂外完成所有这些，在调用程序中：
sc = new SomeClass（）;
删除sc;
SomeClass.constructor.numInstances--;
event = new CustomEvent（）;
alert（" ;对象sc已经被破坏了）;
在我看来它会破坏封装：SomeClass类
在它的边界外流血。 />
感谢您的回复
F.
Ian,
I need to implement it so I can delete an instance and provide at the
same time a chain of actions triggered by the destruction:
sc.destroy() --> deletes sc and --> decrements the number of instances
and --> do some other action (triggers an event, pops up an alert("The
object sc has been destroyed") or some other actions, all part of the
destruction process)
I could do all this outside the class, in the calling procedure:
sc = new SomeClass();
delete sc;
SomeClass.constructor.numInstances--;
event = new CustomEvent();
alert("The object sc has been destroyed");
It seems to me that it would break encapsulation: the SomeClass class
bleeds outsides its boundaries.
Thanks for the reply
F.
Ian，
我需要实现它所以我可以删除一个实例并在
同时提供由销毁触发的一系列动作：
sc.destroy（） - >删除sc和 - >减少实例数
和 - >做一些其他动作（触发事件，弹出警报（
对象sc已被销毁）或其他一些动作，
破坏的所有部分过程）
我可以在课堂外完成所有这些，在调用程序中：
sc = new SomeClass（）;
删除sc;
SomeClass.constructor.numInstances--;
event = new CustomEvent（）;
alert（" ;对象sc已经被破坏了）;
在我看来它会破坏封装：SomeClass类
在它的边界外流血。 />
感谢您的回复
F.
Ian,
I need to implement it so I can delete an instance and provide at the
same time a chain of actions triggered by the destruction:
sc.destroy() --> deletes sc and --> decrements the number of instances
and --> do some other action (triggers an event, pops up an alert("The
object sc has been destroyed") or some other actions, all part of the
destruction process)
I could do all this outside the class, in the calling procedure:
sc = new SomeClass();
delete sc;
SomeClass.constructor.numInstances--;
event = new CustomEvent();
alert("The object sc has been destroyed");
It seems to me that it would break encapsulation: the SomeClass class
bleeds outsides its boundaries.
Thanks for the reply
F.
这篇关于如何实现析构函数？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
