PHP带POST验证的for循环

我刚接触PHP，我正在做一些非常简单的应用程序(测试). 我得到了一个包含以下代码的表单:

if ($_SERVER["REQUEST_METHOD"] == "POST") {
  if (empty($_POST["val1"])) {
    $err_val1 = "Error";
  } else {
    $val1 = test_input($_POST["val1"]);
  }
}

function test_input($data) {
  $data = trim($data);
  $data = stripslashes($data);
  $data = htmlspecialchars($data);
  return $data;
}

<div class='col-lg-1 center'>
<label>1</label>
<input type='text' class='form-control' name='val1'>
<span class='error'><?php echo (!empty($err_val1)) ? 'Error' : '';?></span>
</div>

有没有办法使用for(或Foreach)循环？因为有139个"天"，我想优化代码，避免重复139次相同的部分.

=Edit=

我设法解决了这个问题.

    $errors = [];
    $fields = ['val1', 'val2', 'val3', ...];
    $values = [];
    $values['val1'] = $values['val2'] =$values['val3'] = "";
    
    if ($_SERVER["REQUEST_METHOD"] == "POST") {
      foreach ($fields as $field) {
        if (empty($_POST[$field])) {
          $errors[] = $field;
        } else {
          $values[$field] = $_POST[$field];
        }
      }
    
      if (empty($errors)) {
          ... execute SQL INSERT statement ...
      }

表格

for ($i = 1; $i <= 3; $i++) {
echo "<div class='col-lg-1 center'>";
echo "<label>".$i."</label>";
echo "<input type='text' class='form-control' name='val".$i."' value='".$values['val' . $i]."'>";
if (in_array('val'.$i, $errors)):
echo "<span class='error'>Error</span>";
endif;
echo "</div>";
}