Javascript: Programmatically trigger onbeforeunload/onunload event

Question

How can I programmatically trigger onbeforeunload and onunload events?(No jquery please). I've tried:

 var event = new Event('onbeforeunload'); event.initEvent("onbeforeunload", true, true); window.document.dispatchEvent(event);

Answer 1

window.dispatchEvent(new Event('beforeunload'))

I think this would be the best way in 2020. In case anyone finds this.

window.addEventListener('beforeunload',()=>{console.log("beforeunload triggered")})
window.dispatchEvent(new Event('beforeunload'))

Answer 2

Either use

object.onunload=function(){myScript};

or the addEventListener() method:

object.addEventListener("unload", myScript);

to trigger the event use object.unload();