Compatibility scheme for JavaScript event objects

Traditional registration method:

var div = document.querySelector('div');
div.onclick = function(e) {
    
    
    e = e || window.event;
    console.log(e);
}

AttachEvent event monitoring method:

div.addEventListener('click', function(e) {
    
    
    e = e || window.event;
    console.log(e);
});