The onbeforeunload event occurs when the document is about to be unloaded.
This event allows you to display a message in a confirmation dialog box to inform the user whether he/she wants to stay or leave the current page.
You can use this event as per your need using following approaches mentioned below:
In HTML,
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<!DOCTYPE html> <html> <body onbeforeunload="return yourFunction()"> <script> function yourFunction() { return "Your custom message."; } </script> </body> </html> |
In Javascript,
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<!DOCTYPE html> <html> <body> <script> window.onbeforeunload = function(event) { event.returnValue = "Your custom message."; }; </script> </body> </html> |
In JavaScript, using the addEventListener() method,
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<!DOCTYPE html> <html> <body> <script> window.addEventListener("beforeunload", function(event) { event.returnValue = "Your custom message."; }); </script> </body> </html> |
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