select a one option with js code example

Example 1: 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

Example 2: js select option in form

<form name="AddAndEdit">
   <select name="list" id="personlist">
      <option value="P1">Person1</option>
      <option value="P2">Person2</option>
      <option value="P3">Person3</option>
   </select>
</form>