Question

您好我有这个代码擦除用户输入的页面，如果用户输入的页面编号不是“1000000”，我希望它回显“未找到”我该怎么办？

if (!isset($_POST['submit'])) {
  print "<br><br><br>";
  echo "<center>";
  print "<form action=\"\" method=\"POST\">";
  print "<input name=\"dgt\" id=\"hax\" style=\"width:400px\" type=\"text\">   ";
  print "<input name=\"submit\" value=\"Decrypt Hash\" type=\"submit\">";
  print "</form>";
} else {
  $string = file_get_contents('http://www.md5this.com/list.php?page='.$_POST['dgt']);

  $regex_pattern = "/<tr>([^`]*?)<\/tr>/";

  unset($matches);
  preg_match_all($regex_pattern, $string, $matches);


  foreach ($matches[0] as $paragraph) {
    echo $paragraph;
    echo "<br>";
  }
}

Answer 1

然后检查$matches[0]是否为空。如果没有，请浏览$matches[0]。如果它是空的，那么echo Not found.这是最实用的＆amp;处理您正在处理的数据的现实方法，因为最终您不知道无效页面是什么，因为其他网站是您无法控制的。

if (!isset($_POST['submit'])) {
  print "<br><br><br>";
  echo "<center>";
  print "<form action=\"\" method=\"POST\">";
  print "<input name=\"dgt\" id=\"hax\" style=\"width:400px\" type=\"text\">   ";
  print "<input name=\"submit\" value=\"Decrypt Hash\" type=\"submit\">";
  print "</form>";
}
else {
  $string = file_get_contents('http://www.md5this.com/list.php?page=' . $_POST['dgt']);

  $regex_pattern = "/<tr>([^`]*?)<\/tr>/";

  unset($matches);
  preg_match_all($regex_pattern, $string, $matches);

  if(!empty($matches) && !empty($matches[0])) {
    foreach ($matches[0] as $paragraph) {
      echo $paragraph;
      echo "<br>";
    }
  }
  else {
    echo 'Not found.';
  }
}

Answer 2

如果我理解正确，这应该有效

if (!isset($_POST['submit'])) {
     print "<br><br><br>";
     echo "<center>";
     print "<form action=\"\" method=\"POST\">";
     print "<input name=\"dgt\" id=\"hax\" style=\"width:400px\" type=\"text\">   ";
     print "<input name=\"submit\" value=\"Decrypt Hash\" type=\"submit\">";
     print "</form>";
} else {


    if($_POST['dgt'] < 1000000){

      $string = file_get_contents('http://www.md5this.com/list.php?page='.$_POST['dgt']);

      $regex_pattern = "/<tr>([^`]*?)<\/tr>/";

      unset($matches);
      preg_match_all($regex_pattern, $string, $matches);

      foreach ($matches[0] as $paragraph) {
        echo $paragraph;
        echo "<br>";
      }


    }else{

            echo "Not Found";
    }


}

如果结果为空，则找不到echo

2 个答案: