javascript cannot remove event listener onbeforeunload from list

Question

I tried all possible ways to remove an event from window object :

window.onbeforeunload = null;
window.BeforeUnloadEvent = null;
$(window).unbind('beforeunload');
$(window).off('onbeforeunload');
window.removeEventListener('beforeunload', carol, true);
window.removeEventListener('onbeforeunload', carol, true); // carol is that function see image below 

and when i type getEventListener(window) is still present there

does anybody know another way or am i doing something wrong ?

Answer 1

The leading "on" is only used when event listeners are accessed as object properties. When removing the event, just use the event name:

 window.removeEventListener('beforeunload', carol, true);