.splice() issue

As you can see my comment, I’m not sure why I’m getting an empty array and not [‘dog’, ‘cat’, foo’, ‘bar’]

var list = ["foo", "bar"];
function addElements(startIndex, itemsToDelete, item1, item2) {
  var newArray = list.splice(startIndex, itemsToDelete, item1, item2) 
  return newArray

addElements(0, 0, "dog", "cat") // why does it return an empty array and not ['dog', 'cat', 'foo', 'bar']?

Return value

An array containing the deleted elements.

If only one element is removed, an array of one element is returned.

If no elements are removed, an empty array is returned.