语法错误，意外T_CONSTANT_ENCAPSED_STRING [关闭]

Question

Faced with such a mistake "syntax error, unexpected T_CONSTANT_ENCAPSED_STRING in" I understand that something with quotes and that is just not visited is not what does not work what could be the problem

if (!session_admin ())
  {
    @header ('Location: ' . $CONFIG['SITE_URL']);
  }

  if (($_POST['Action'] == 'Save' AND $_POST['submit']))
  {
    foreach ($_POST as $key => $value)
    {
  --->    if ((($key != 'submit' AND $key != 'Action') AND $key != 'selectedtab') AND !isset ('key'))
      {
        if ((($key == 'SITE_TEMPLATE' AND $value != $CONFIG['SITE_TEMPLATE']) AND !$recache))
        {
          $recache = true;
        }

        $SQL = 'UPDATE ' . $_settings . ' SET value=\'' . $value . '\' WHERE setting=\'' . $key . '\'';

      }

      $$fieldname = trim ($value);
    }

    $Success[] = 'Site settings updated successfully.';
    if ($recache)
    {
      @header ('Location: ' . @get_link ($cur_page . '?recache=true'));
    }
    else
    {
      if ((!$Error AND $CONFIG['caching_status']))
      {
        empty_cache_folder ();
      }
    }
  }

Answer 1

The following is invalid

!isset ('key'))

Replace it with

!isset($key))

I've also tidied your code, to make it more readable.

<?php

if (!session_admin()) {
    //Try not to suppress errors, but handle them instead
    @header('Location: ' . $CONFIG['SITE_URL']);
    exit; //Always kill the script after issuing a header('Location
}

if (($_POST['Action'] == 'Save' AND $_POST['submit'])) {
    foreach ($_POST as $key => $value) {
        if ((($key != 'submit' AND $key != 'Action') AND $key != 'selectedtab') AND !isset($key)) {
            if ((($key == 'SITE_TEMPLATE' AND $value != $CONFIG['SITE_TEMPLATE']) AND !$recache)) {
                $recache = true;
            }

            $SQL = 'UPDATE ' . $_settings . ' SET value=\'' . $value . '\' WHERE setting=\'' . $key . '\'';
        }

        $fieldname = trim($value);
    }

    $Success[] = 'Site settings updated successfully.';
    if ($recache) {
        //Try not to suppress errors, but handle them instead.
        @header('Location: ' . @get_link($cur_page . '?recache=true'));
        exit; //Always kill the script after issuing a header('Location
    } else {
        if ((!$Error AND $CONFIG['caching_status'])) {
            empty_cache_folder();
        }
    }
}