c:remove

In a JSP page, we can use the JSTL tag c:set to remove objects, passing null as a value. It works, but it is not exactly what one would call a reader friendly way to do it.

Better using c:remove instead.

Here we create an attribute in the request scope using c:set, we show it to the user, and then remove it using c:remove. The scope attribute is optional, but be careful, when not specified all the attribute with the passed name are removed from all the scopes.

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<!-- ... -->

<c:set var="userStatus" scope="request" value="Brilliant" />
<br />userStatus: ${userStatus}
<c:remove var="userStatus" scope="request" />
<br />userStatus is now: ${userStatus}

More on JSTL in chapter nine of Head First Servlet and JSP.