addeventlistener javascript onchange code example

Example 1: javascript add function to onchange event

transport_select.setAttribute("onchange", function(){toggleSelect(transport_select_id);});
// or
transport_select.onchange = function(){toggleSelect(transport_select_id);};

Example 2: handling event changes

<button>Click me any way you want</button>
<script>
  let button = document.querySelector("button");
  button.addEventListener("mousedown", event => {
    if (event.button == 0) {
      console.log("Left button");
    } else if (event.button == 1) {
      console.log("Middle button");
    } else if (event.button == 2) {
      console.log("Right button");
    }
  });
</script>