What are window.opener / window.parent / window.top?

javascript, window

Solution

- `window.opener` refers to the window that called `window.open( ... )` to open the window from which it's called

- `window.parent` refers to the parent of a window in a `<frame>` or `<iframe>`

- `window.top` refers to the top-most window from a window nested in one or more layers of `<iframe>` sub-windows

Those will be `null` (or maybe `undefined`) when they're not relevant to the referring window's situation. ("Referring window" means the window in whose context the JavaScript code is run.)

Problem

Original source