<html><body><h1>input pattern 属性</h1><p>这个表单的密码字段必须包含 8 个或更多字符：</p><form action="/demo/action_page.php"> <label for="pwd">密码：</label> <input type="password" id="pwd" name="pwd" pattern=".{8,}" title="八个或更多字符"> <input type="submit"></form></body></html>