how to get selected value in select html code example

Example 1: get selected option value

var conceptName = $('#aioConceptName').find(":selected").val();

Example 2: html get selected option javascript

<select id="ddlViewBy">
  <option value="1">test1</option>
  <option value="2" selected="selected">test2</option>
  <option value="3">test3</option>
</select>

<script>
    var e = document.getElementById("ddlViewBy");
	var strUser = e.value; // 2
	var strUser = e.options[e.selectedIndex].text; //test2
</script>

Example 3: javascript get selected option

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