JSTL c:forEach, decremental number loop impossible?

Question

I want to print decremental numbers like:

<c:forEach var="i" begin="10" end="0" step="-1">
    ... ${i} ...
</c:forEach>

then I got jsp exception:

javax.servlet.jsp.JspTagException: 'step' <= 0
    javax.servlet.jsp.jstl.core.LoopTagSupport.validateStep(LoopTagSupport.java:459)
    org.apache.taglibs.standard.tag.rt.core.ForEachTag.setStep(ForEachTag.java:60)
    ....

but this answer says it is possible to loop in both ways:

JSTL forEach reverse order

What's wrong with me?

Solution 1

I am not sure how the answerer of the other question got it to work, but I can't get it to work here with the reference JSTL implementation.

Anyway, you can achieve the requirement with following:

<c:forEach var="i" begin="0" end="10" step="1">
    ... ${10 - i} ...
</c:forEach>

Or if you'd like to avoid duplication of 10:

<c:forEach var="i" begin="0" end="10" step="1" varStatus="loop">
    ... ${loop.end - i + loop.begin} ...
</c:forEach>

Solution 2

A possible solution, without using the var attribute:

<c:forEach begin="0" end="10" varStatus="loop">
  ${loop.end - loop.count + 1}
</c:forEach>

Note that step is omitted too, because its default value is 1.