how to do i find out the length of this arraylist using JSTL tags...

or if

<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
${fn:length(theList)}

how to do i find out the length of this arraylist
using JSTL tags...

/That depends on what version of what server (and JSTL) you are using. If you are using JSTL 1.1 (JSP 2.0 server like Tomcat 5.0) then you can use:

<br /><c:set var="count" value="${fn:length(requestScope.array)}"/><br />

If you are Using JSTL 1.0 and a JSP 1.2 server (like Tomcat 4), then you will either have to use a scriptlet, or run a c:forEach:

//scriptlet
<%
List array = (List)request.getAttribute("array");
Integer count = new Integer(array.size());
pageContext.setAttribute("count", count);
%>
//c:forEach

<br /><c:forEach var="something" items="${requestScope.array}" varStatus="status"><br /> <c:if test="${status.last}"><c:set var="count" value="${status.count}"/></c:if><br /></c:forEach><br />