取得不到post數據

Question

<?php
header("Content-type:text/html;charset=utf-8");

echo <<<'FROM'
#< from action="" method="post">
   請輸入整數：
   <input type="number" name="num">
   <input type="submit" valuetype="submit" value ="提交">

</from>
FROM;

echo isset($_POST['num']);

Answer 1

知道了 form寫反了

Answer 2

請問有大佬知道什麼原因嗎