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Window: closed property - Web APIs | MDN
A boolean value. Possible values:
true
: The window has been closed.
false
: The window is open.
The following example demonstrates how a popup window can change the URL of the window
that opened it. Before attempting to change the URL, it checks that the current window
has an opener using the window.opener
property and that the opener isn't
closed:
// Check that an opener exists and is not closed
if (window.opener && !window.opener.closed) {
window.opener.location.href = "https://www.mozilla.org";
}
Note that popups can only access the window that opened them.
In this example the function refreshPopupWindow()
calls the
reload()
method of the popup's location object to refresh its data. If the
popup hasn't been opened yet or the user has closed it a new window is opened.
let popupWindow = null;
function refreshPopupWindow() {
if (popupWindow && !popupWindow.closed) {
// popupWindow is open, refresh it
popupWindow.location.reload(true);
} else {
// Open a new popup window
popupWindow = window.open("popup.html", "dataWindow");
}
}