how to access an element of arraylist in jsp when index is a variable?

Question

i m accessing an element in an arraylist. the problem arises as the index of the required element is a variable. can anyone plz help me?

eg <td><c:out value="${PARENT_MODULE[module.moduleId]}"> </c:out></td>

here module.moduleId is a variable.

i have already tried

<c:out value="${PARENT_MODULE[${module.moduleId}]}">

however this gives an error.

org.apache.jasper.JasperException: /WEB-INF/jsp/showModules.jsp(40,20) "${PARENT_MODULE[${module.moduleId}]}" contains invalid expression(s): javax.el.ELException: Error Parsing: ${PARENT_MODULE[${module.moduleId}]}

thanks

You don't need to use ${} around `module.moduleId`, `` should work. — obourgain, Feb 27 '13 at 09:11
thank you so much! i never tried that.. as i thought that was highly unlikely.. — Shubham, Feb 27 '13 at 09:26

score 6 · Answer 1 · answered Feb 27 '13 at 10:09

6

As module.moduleId is inside an EL expression, it will be evaluated. So you don't need to enclose it in an additional ${}.

<c:out value="${PARENT_MODULE[module.moduleId]}"> will work.

answered Feb 27 '13 at 10:09

obourgain

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score 2 · Accepted Answer · edited Mar 03 '13 at 02:33

2

Assuming PARENT_MODULE is the alias you gave the array of modules Assuming module is the object and moduleId is an attribute in the module object

try this:

< c:out value="${PARENT_MODULE[num].moduleId}"/>

where num is a number. PARENT_MODULE[num] would return the object module at the "num" position in the array. and after that all you have to do is access the moduleId attribute.

edited Mar 03 '13 at 02:33

Bernie

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answered Mar 03 '13 at 01:58

Shardayyy

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how to access an element of arraylist in jsp when index is a variable?

2 Answers2