how to get select box value in javascript 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 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 3: select box get value

// reference to 'scripts' select list 
// used throughout the examples below
var sel = document.getElementById('scripts');

// display value property of select list (from selected option)
console.log( sel.value );