The top, parent, and opener meanings of the JS window object

1. Top
   This change always refers to the top-level browser window of the split window. If you plan to execute commands from the top level of the split window, you can use the top variable.
2. Opener
   Opener The object that is used to refer to the page that executes the window.open method on the window.open page. Example: a page through window.open () party
   Method pops up the B page, in the B page can be opener to refer to a page, so you can use this object to the a page operation.
3. Parent
   The parent is used to access the object in the child page that is generated in iframe,frame. For example: A page has an IFRAME or frame, then the IFRAME
   or a page in a frame can refer to an object in page A through the parent object. This allows you to get or return a value to the a page.
   4. In addition, self refers to the current window
4. Self
   Self refers to the current window

The difference between parent and opener:

Parent refers to the Father window, and in frameset, the parent of the frame is the frameset window.
Opener refers to the original window corresponding to a new window created with window.open.
The parent is an object that is relative to the frame.
Opener is the parent window for a window opened with window.open, provided the window.open is open.

Document.parentWindow.menthod () method that invokes the parent page.

Attached: Hierarchy Relationship of Window object, parent object, frame object, Document object, and Form object
The Window object →parent object →frame Object →document object →form object,
as follows: Parent.frame1.document.forms[0].elements[0].value;

The top, parent, and opener meanings of the JS window object