how to get selected value of drop down code example

Example 1: 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

Example 2: javascript to get value of dropdown

var e = document.getElementById("elementId");
var value = e.options[e.selectedIndex].value;
var text = e.options[e.selectedIndex].text;

Example 3: selected dropdown value

Plain JavaScript:
===================
var e = document.getElementById("elementId");
var value = e.options[e.selectedIndex].value;
var text = e.options[e.selectedIndex].text;
---------------------------------------------------------
jQuery:
=======
$("#elementId :selected").text(); // The text content of the selected option
$("#elementId :selected").val(); // The value of the selected option