Why the following error is coming in smarty foreach loop? - foreach

Question

Following is my code of foreach loop in smarty template:
{if $question_detail.question_has_sub_ques=='yes' && $question_detail.sub_question}
{foreach from=$question_detail.sub_question item=sub_ques_ans key=sub_ques_no}
<tr class="oddRow">
<td class="question">
<h4><strong>Sub-question {$page_question_no+1}.{$sub_ques_no+1}</strong></h4>
<ul class="options">
<li><span>{$sub_ques_ans.question_text}</span></li>
</ul>
</td>
<td class="question-id">QUE{$sub_ques_ans.question_id}</td>
</tr>
{if $sub_ques_ans.question_file!=''}
<tr>
<td valign="top" colspan="2">
<img src="{$ques_thum_image_path}{$sub_ques_ans.question_id}_{$sub_ques_ans.question_file}">
</td>
</tr>
{/if}
{if $question_detail.sub_question_answer_{$page_question_no+1}}
<tr class="question_answer evenRow">
<td class="question">
<p class="answers"><strong>Answers</strong></p>
<ol class="options">
**{foreach from=$question_detail.sub_question_answer_{$page_question_no+1} item=sub_ans key=sub_ans_no}**
<li>
{if $sub_ans.answer_is_right==1} {assign var='correct_sub_ans' value=$sub_ans_no+1} {/if}
{if $sub_ans.answer_text!=''}{$sub_ans.answer_text}{/if}<br />
{if $sub_ans.answer_file!=''}<img src="{$ans_thumb_img_path}{$sub_ans.answer_id}_{$sub_ans.answer_file}" >{/if}
</li>
{/foreach}
</ol>
<p class="correct-answer"><strong>Correct Answer Option : </strong>{$correct_sub_ans}</p>
</td>
<td class="question-id"> </td>
</tr>
{/if}
{/foreach}
{/if}
I'm getting error as follows:
Fatal error: Smarty error: [in question-details.tpl line 66]:
syntax error: foreach: missing 'item' attribute (SmartyCompiler.php, line 1179) in /var/www/eprime/ocn/core/libs/Smarty.php on line 1095
And the line no.66 in my code is:
{foreach from=$question_detail.sub_question_answer_{$page_question_no+1} item=sub_ans key=sub_ans_no}
Can anyone help me in correcting this error? Any kind of help would be highly appreciated.

Answer 1

Try this
{assign var="condition" value="{$question_detail.sub_question_answer}_{$page_question_no+1}"}
{foreach from=$condition item=sub_ans key=sub_ans_no}
// do your code
{/foreach}