[javascript] How can I determine the direction of a jQuery scroll event?

Keep it super simple:

jQuery Event Listener Way:

$(window).on('wheel', function(){
  whichDirection(event);
});

Vanilla JavaScript Event Listener Way:

if(window.addEventListener){
  addEventListener('wheel', whichDirection, false);
} else if (window.attachEvent) {
  attachEvent('wheel', whichDirection, false);
}

Function Remains The Same:

function whichDirection(event){
  console.log(event + ' WheelEvent has all kinds of good stuff to work with');
  var scrollDirection = event.deltaY;
  if(scrollDirection === 1){
    console.log('meet me at the club, going down', scrollDirection);
  } else if(scrollDirection === -1) {
    console.log('Going up, on a tuesday', scrollDirection);
  }
}

I wrote a more indepth post on it here ???????