<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title></title>
<meta charset="utf-8" />
<script src="jquery-3.3.1.js"></script>
<script>
var msg = ' hello ';
alert('==='+$.trim(msg)+'==='); </script>
</head>
<body>
</body>
</html>