javascript get selected option

var e = document.getElementById("selectElementID");
var value=e.selectElement.options[e.selectedIndex].value;// get selected option value
var text=e.options[e.selectedIndex].text;//get the selected option text

let selectElement = document.getElementById("selectElement");
let valueSelected = selectElement.options[selectElement.selectedIndex].value; // get selected option value
var text= selectElement.options[selectElement.selectedIndex].text; //get the selected option text