javascript - JS restore default/global functions -

This is a fictional question, it is not really practical use, but ...

Value Take that you had to:

  document.open = null;   
 How to restore a document. Opening its original functionality, is it possible (without temporary storage created by the user)? Is document.open stored in another place under a lower name? Thanks!   
 
 
 Overwriting a  function called  document.open  Open  document  directly to the object  However, the original function was not on the object, but its prototype - so that you can actually restore it.  
  open  function is  HTMLDocument.prototype  so you can do this by  HTMLDocument.prototype.open . You can access it by using it.  
 To call it directly, specify the object to use  .call ()  on it:  
  HTMLDocument.prototype. Open.call (document, ...); You can also restore  document.open  by simply specifying it:  
  document.open = HTMLDocument.prototype .open;   
 However, remember that  HTMLDocument  and thus  documents  are hosted objects and usually a good idea to mess with them. There is no - especially if you do so IE things may be bad.