Question

I got the following code:

<c:forEach var="i" begin="1" end="${finalDisccount}">
                <p><c:out value="${tracksCD}" /> Tracks für CD${i} hochladen</p>
                <p><input id="filename_${i}" type="file" name="filename_${i}" size="50" multiple="multiple" required="required"/></p>
</c:forEach>

The value “tracksCD” has be to concatenated with the variable i, so that something like this is created by the loop:

<p><c:out value="${tracksCD1}" /> Tracks für CD${i} hochladen</p>
<p><c:out value="${tracksCD2}" /> Tracks für CD${i} hochladen</p>

And so on.
Is there a way to combine ${tracksCD} and ${i} to get ${tracksCD1} and so on dynamically?

Thanks in advance.

Answer 1

If you know the scope of the data, then you can just access it in the scope map ${requestScope}, ${sessionScope} or ${applicationScope}. E.g. when it’s in the request scope:

<c:forEach var="i" begin="1" end="${finalDisccount}">
    <c:set var="tracksCDKey" value="${tracksCD}${i}" />
    <p><c:out value="${requestScope[tracksCDKey]}" /> Tracks für CD${i} hochladen</p>
    <p><input id="filename_${i}" type="file" name="filename_${i}" size="50" multiple="multiple" required="required"/></p>
</c:forEach>

However, you’ve there a pretty nasty design mistake. Rather collect them in an array or a list as ${tracksCDs} so that you can do as follows:

<c:forEach var="i" begin="1" end="${finalDisccount}">
    <p><c:out value="${tracksCDs[i - 1]}" /> Tracks für CD${i} hochladen</p>
    <p><input id="filename_${i}" type="file" name="filename_${i}" size="50" multiple="multiple" required="required"/></p>
</c:forEach>

Or maybe if the ${finalDisccount} happen to have the same size as the array/list:

<c:forEach items="${tracksCDs}" var="${tracksCD}" varStatus="loop">
    <p><c:out value="${tracksCD}" /> Tracks für CD${loop.count} hochladen</p>
    <p><input id="filename_${loop.count}" type="file" name="filename_${loop.count}" size="50" multiple="multiple" required="required"/></p>
</c:forEach>