How to scroll a scrollable div while scrolling to another, without a scrollable div?

Question

I know the question sounds confusing, but here's what I'm trying to do - in the snippet below, if the user scrolls through the green div, I want the yellow div to be scrolled accordingly, as if the yellow div had been scrolled.

Note that the yellow div has overflow: auto;, but the green does not.

document.getElementById('green').addEventListener('wheel', function(e){

  console.log('scrolled!');

  console.log(e.deltaX); // it is always "-0"

  // scroll div#yellow accordingly

});

#yellow{
  background-color: yellow;
  display: inline-block;
  width: 200px;
  height: 200px;
  overflow: auto;
  vertical-align: top;
  padding 20px;
}

#green{
  background-color: green;
  display: inline-block;
  width: 100px;
  height: 200px;
  vertical-align: top;
}

<div id='yellow'>
  <p>1</p>
  <p>2</p>
  <p>3</p>
  <p>4</p>
  <p>5</p>
  <p>6</p>
  <p>7</p>
  <p>8</p>
  <p>9</p>
  <p>10</p>
</div>

<div id='green'></div>

Run codeHide result

How do I achieve this?

Answer 1

You are trying to get a property deltaX, and what you need for vertical scrolling is this deltaY.

document.getElementById('green').addEventListener('wheel', function(e){
  e.preventDefault();
  document.getElementById('yellow').scrollTop += e.deltaY * 10;
});

Answer 2

Try this DEMO

document.getElementById('green').addEventListener('wheel', function(e) {


  console.log(e.deltaY); // it is always "-0"

  // scroll div#yellow accordingly
  document.getElementById('yellow').scrollTop += e.deltaY;
});



#yellow {
  background-color: yellow;
  display: inline-block;
  width: 200px;
  height: 200px;
  overflow: auto;
  vertical-align: top;
  padding 20px;
}
#green {
  background-color: green;
  display: inline-block;
  width: 100px;
  height: 200px;
  vertical-align: top;
}



<div id='yellow'>
  <p>1</p>
  <p>2</p>
  <p>3</p>
  <p>4</p>
  <p>5</p>
  <p>6</p>
  <p>7</p>
  <p>8</p>
  <p>9</p>
  <p>10</p>
</div>

<div id='green'>
  <p>1</p>
  <p>2</p>
  <p>3</p>
  <p>4</p>
  <p>5</p>


</div>