title: PHP-Warning: array_map(): Argument #2 should be an array
body: <p>I have this Code for fetch data from MySql database:</p>
  
  <pre><code>   $sql = 'SELECT id,title,seotitle FROM ' . PROPERTIES_TABLE  . ' WHERE featured = "A" AND approved = 1 AND id = "' . safe($_GET['id']) . '" LIMIT 1';
     $r = $db-&gt;query ( $sql ) or error ('Critical Error' , mysql_error());
     $f = $db-&gt;fetcharray( $r );
    // Make all values in the array 'n/a' if empty
     $f = array_map ( 'if_empty', $f);  
  </code></pre>
  
  <p>if_empty is:</p>
  
  <pre><code>function if_empty ( $value ) 
  
   { 
  
    if ($value == '' || $value == '0') 
     return ''; 
    else 
     return $value; 
  
   }
  </code></pre>
  
  <p>Now, I see this error:</p>
  
  <pre><code>Warning: array_map(): Argument #2 should be an array in C:\xampp\htdocs\cms\qrcode.php on line 26
  </code></pre>
  
  <p>how can i fix this ?</p>