PHP搜索结果中的高亮关键词

Question

我有以下代码，我正在尝试突出显示回显结果的搜索关键字。我试过here 和here 但是没有工作。

我在哪里弄错了。

以下是我的代码

if (isset($_GET["mainSearch"])) 
{
  $condition = '';
  // $mainSearch = SQLite3::escapeString($_GET['mainSearch']);
  $keyword = $_GET['mainSearch'];
  $query = explode(" ", $keyword);

  foreach ($query as $text) 
  {
      $condition .= "question LIKE '%".SQLite3::escapeString($text)."%' OR ";
  }
  $condition = substr($condition, 0, -4);


  $order = " ORDER BY quiz_id DESC ";
  $sql_query = "SELECT * FROM questions WHERE " . $condition . ' '. $order;
  $sql_query_count = "SELECT COUNT(*) as count FROM questions WHERE " . $condition .' '. $order;
  $result = $db->query($sql_query);
  $resultCount = $db->querySingle($sql_query_count);

  if ($resultCount > 0)
  {
  if ($result)
  {
      while ($row = $result->fetchArray(SQLITE3_ASSOC))
      {
          //TRYING TO HIGHLIGHT SEARCH KEYWORD HERE. 
          $wording = str_replace($keyword, "<span style='font-weight: bold;'>".$keyword."</span>", $row['answer']);

           echo '<div class="quesbox_3">
            <div class="questitle">
                <h2>'.$row["question"].'</h2>
            </div>
            <div class="quesanswer">'.$wording.'</div>
        </div>';
      }
  }
  }
  else
  {
      echo "No results found";
  }
}

非常感谢。