Expression Language (EL)
We now turn our attention to the Expression Language. Although EL is not a general purpose programming language, it does share many characteristics with common languages with which you will be familiar. For example, while it has no flow-control it does have variables and operators.
EL variables are implicit JSP variables, additional EL-specific variables, and any user-defined variables. Today's discussion will focus on using implicit variables and using JavaBeans (see the section “Simplifying JSP pages with JavaBeans”). Setting variables using the JSTL is covered on Day 14.
Like JSP, EL defines a number of implicit objects that provide access to request parameters, HTTP headers, cookies, ...