Trying to detect browser close event

Question

I have tried many methods to detect browser close event through jQuery or JavaScript. But, unfortunately, I have not been able to detect the close. The onbeforeunload<

Answer 1

Referring to various articles and doing some trial and error testing, finally I developed this idea which works perfectly for me.

The idea was to detect the unload event that is triggered by closing the browser. In that case, the mouse will be out of the window, pointing out at the close button ('X').

$(window).on('mouseover', (function () {
    window.onbeforeunload = null;
}));
$(window).on('mouseout', (function () {
    window.onbeforeunload = ConfirmLeave;
}));
function ConfirmLeave() {
    return "";
}
var prevKey="";
$(document).keydown(function (e) {            
    if (e.key=="F5") {
        window.onbeforeunload = ConfirmLeave;
    }
    else if (e.key.toUpperCase() == "W" && prevKey == "CONTROL") {                
        window.onbeforeunload = ConfirmLeave;   
    }
    else if (e.key.toUpperCase() == "R" && prevKey == "CONTROL") {
        window.onbeforeunload = ConfirmLeave;
    }
    else if (e.key.toUpperCase() == "F4" && (prevKey == "ALT" || prevKey == "CONTROL")) {
        window.onbeforeunload = ConfirmLeave;
    }
    prevKey = e.key.toUpperCase();
});

The ConfirmLeave function will give the pop up default message, in case there is any need to customize the message, then return the text to be displayed instead of an empty string in function ConfirmLeave().