PHP 字符串搜索和替换 - 可能需要使用 DOM

我似乎无法弄清楚如何实现我的目标。

我想根据生成的 RSS 提要查找并替换特定的类链接（无论有什么链接，都需要稍后替换的选项）

示例 HTML：

<a class="epclean1" href="#">

它应该是什么样子：

<a class="epclean1" href="google.com">

可能需要使用 DOM 合并 get 元素，因为 Full php 有一个创建的文档。如果是这种情况，我需要知道如何按类查找并以这种方式添加 href url。

完整的PHP：

<?php 
$rss = new DOMDocument(); 
$feed = array();
$urlArray = array(array('url' => 'https://feeds.megaphone.fm')
);

foreach ($urlArray as $url) {
    $rss->load($url['url']);

        foreach ($rss->getElementsByTagName('item') as $node) {
            $item = array ( 
                'title' => $node->getElementsByTagName('title')->item(0)->nodeValue
                );
            array_push($feed, $item);
        }
    }

    usort( $feed, function ( $a, $b ) {
                return strcmp($a['title'], $b['title']); 
    });

    $limit = sizeof($feed);
    $previous = null;
    $count_firstletters = 0;
    for ($x = 0; $x < $limit; $x++) {
        $firstLetter = substr($feed[$x]['title'], 0, 1); // Getting the first letter from the Title you're going to print
        if($previous !== $firstLetter) { // If the first letter is different from the previous one then output the letter and start the UL
            if($count_firstletters != 0) {
                echo '</ul>'; // Closing the previously open UL only if it's not the first time
                echo '</div>';

            }
            echo '<button class="glanvillecleancollapsible">'.$firstLetter.'</button>';
            echo '<div class="glanvillecleancontent">';
            echo '<ul style="list-style-type: none">';
            $previous = $firstLetter;
            $count_firstletters ++;
        }   
        $title = str_replace(' & ', ' &amp; ', $feed[$x]['title']); 
        echo '<li>'; 
        echo '<a class="epclean'.$i++.'" href="#" target="_blank">'.$title.'</a>';
        echo '</li>';
    }
    echo '</ul>';  // Close the last UL
    echo '</div>';
    ?>
      </div>
    </div>

上面的 fullphp 在网站上显示如下（由于有 200 多个，因此缩短了）：

    <div class="modal-glanvillecleancontent">
        <span class="glanvillecleanclose">×</span>

    <p id="glanvillecleaninstruct">Select the first letter of the episode that you wish to get clean version for:</p>
    <br>


     <button class="glanvillecleancollapsible">8</button>
<div class="glanvillecleancontent">
<ul style="list-style-type: none">
<li><a class="epclean1" href="#" target="_blank">80's Video Vixen Tawny Kitaen 044</a></li>
</ul>
</div>
<button class="glanvillecleancollapsible">A</button>
<div class="glanvillecleancontent">
<ul style="list-style-type: none">
<li><a class="epclean2" href="#" target="_blank">Abby Stern</a></li>
<li><a class="epclean3" href="#" target="_blank">Actor Nick Hounslow 104</a></li>
<li><a class="epclean4" href="#" target="_blank">Adam Carolla</a></li>
<li><a class="epclean5" href="#" target="_blank">Adrienne Janic</a></li>
</ul>
</div>