4. Program to find length of a string

<!DOCTYPE html>
<html lang="en">
<meta charset="utf-8">
<html>
   <head>
      <title>Problem to find length of a string</title>
   </head>
   <body>   
      <script type = "text/javascript">
         var str = new String( "This is a new string" );
         document.write("str.length is:" + str.length); 
        //string length is 20
      </script>      
   </body>
</html>