Onunload doesn't work in JS

Question

window.onunload = function()
{
    confirm("close the window?")
}

Why don't I have the confirm window coming out when closing a window?

window.onunload is not universally supported and where it is, its implementation can vary. Don't rely on it. — , Apr 29 '14 at 06:52
Try to use "onbeforeunload" instead. Don't use `confirm`, just return a string from the event handler. The browser will take care of the confirmation message box all by itself, presenting the message you returned from the event handler — devnull69, Apr 29 '14 at 06:53

score 0 · Answer 1 · answered Apr 29 '14 at 06:52

Presumably it is to prevent pages from repeatedly preventing you from closing a page. With the beforeunload event, you can, however, get what is, in most modern browsers, a non-customizable or only partly customizable dialog prompting the user whether to leave or not.

score 0 · Answer 2 · edited May 23 '17 at 12:11

0

Many browsers not support window.unload.

Please view this link.

window.onbeforeunload and window.onunload is not working in Firefox , Safari , Opera?

edited May 23 '17 at 12:11

Community

1
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answered Apr 29 '14 at 06:53

HarisJayadev

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12

score 0 · Answer 3 · edited May 23 '17 at 12:11

0

Most browsers prevent the use of alert/confirm in onunload. Instead use an onbeforeunload handler that returns a string:

window.onbeforeunload = function() {
    return "Don't go!";
};

This will then be presented to the user in a dialogue box.

See also: window.unload() won't work in jQuery

edited May 23 '17 at 12:11

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answered Apr 29 '14 at 06:54

James Hibbard

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Onunload doesn't work in JS

3 Answers3