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 is used to reference the object of 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.
The 3.parent 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

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.
Parent is relative to the frame in which the parents window object
Opener is the parent window for a window opened with window.open, provided the window.open is open.

Document.parentWindow.menthod () How to adjust 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;

(RPM) The top, parent, opener meaning of the JS window object