集合的一个小发现

<c:forEach items="${sessionScope.singleProblems}" var="singleProblem" varStatus="statu">
    <h4>${statu.count}.${singleProblem.title}</h4>
    <c:if test="${user.roleId == 2}">
        (正确答案是${singleProblem.answer}）
    </c:if>
    <table class="table table-striped table-bordered">
        <tr>
            <td>A:<label><input type="radio" name="singleProblem_Answer_${statu.count}" ${requestScope.StudentSingleProblemAnswer[statu.index].userAnswer eq 'A' ? 'checked' : 'disabled'} >${singleProblem.answerA}</label></td>

            <td>B:<label><input type="radio" name="singleProblem_Answer_${statu.count}" ${StudentSingleProblemAnswer[statu.index].userAnswer eq 'B' ? 'checked' : 'disabled'}>${singleProblem.answerB}</label></td>
        </tr>
        <tr>
            <td>C:<label><input type="radio" name="singleProblem_Answer_${statu.count}" ${StudentSingleProblemAnswer[statu.index].userAnswer eq 'C' ? 'checked' : 'disabled'}>${singleProblem.answerC}</label></td>
            <td>D;<label><input type="radio" name="singleProblem_Answer_${statu.count}" ${StudentSingleProblemAnswer[statu.index].userAnswer eq 'D' ? 'checked' : 'disabled'}>${singleProblem.answerD}</label></td>
    </table>
</c:forEach>