对于包含数组的循环不适合我

Question

这里的简单问题。为什么会出错？

  for ($k = 1; $k < 17; $k++){

 echo $result[0]->answer_."$k";

}

编辑：$ result的内容：

数组（[0] =＆gt; stdClass对象（[entry_id] =＆gt; 37 [answer_1] =＆gt; 20-24岁[answer_2] =＆gt;否[answer_3] =＆gt;是[answer_4] = ＆gt;没有[answer_5] =＆gt; 236.7 [answer_6] =＆gt;理想的血压 - 91和120之间的上限数字，61和80之间的较低数字[answer_7] =＆gt;不，我没有检查过[ answer_8] =＆gt;不，我退出超过10年[answer_9] =＆gt;我有时每周得150分钟或更长时间[answer_10] =＆gt;每天2-5小时[answer_11] =＆gt;每天[ answer_12] =＆gt;经常或不经常[answer_13] =＆gt;每天[answer_14] =＆gt;一周3-4天[answer_15] =＆gt;从不[answer_16] =＆gt;帝国））

Answer 1

尝试

for ($k = 1; $k < 17; $k++){

    echo $result[0]->{'answer_'.$k};

}

根据以下mpen的评论更新