JSFiddle - React, Tailwind, and code Playground

HTML

<select class="month" type="text" id="birth-month">
     <option value="1">01</option>
     <option value="2">02</option>
     <option value="3">03</option>
     <option value="4">04</option>
     <option value="5">05</option>
     <option value="6">06</option>
     <option value="7">07</option>
     <option value="8">08</option>
     <option value="9">09</option>
     <option value="10">10</option>
     <option value="11">11</option>
     <option value="12">12</option>
</select>

<div id="out"></div>

JavaScript

var $out = $('#out');

$('#birth-month').bind('change', function() {
    var $$ = $(this);
    
    var v = $$.val();
    var l = v.length;
    
    var s = $$.val().toString();
    var sL = s.length;
    
    $out.html('<p>value = ' + v + '</p>' +
              '<p>length = ' + l + '</p>' + 
              '<p>to string value = ' + s + '</p>' +
              '<p>to strign length = ' + sL + '</p>');
    
    alert(typeof v);
});