未定义的偏移1错误

Question

$div_odds = $div - > getElementsByTagName('div');
foreach($div_odds as $od) {
    $class_od = $od - > getAttribute('class');
    if ($class_od == 'CSegno') {
      $expolde = preg_split('/\n|\r\n?/', $div - > textContent);
      $part - > type = explode('Segno:', $expolde[3])[1];
      $part - > cote = str_replace(',', '.', preg_replace('/\s+/', '', $expolde[2]));
    }

它显示以下错误消息：

  

＆＃39;未定义的偏移量1＆＃39;