PHP rss按字母顺序排序并显示标题上方的第一个字母

Question

PHP to display feed items and list them alphabetically and display first letter of each title above. It is only show one letter above the whole list and it is the letter of the first title on the feed. I changed feedurl here for privacy purposes. Any Ideas?

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

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']); 
});
$previous = null;
foreach($item as $value) {
    $firstLetter = substr($value, 0, 1);
    if($previous !== $firstLetter) 
    $previous = $firstLetter;

}
$limit = 3000;
echo '<p>'.$firstLetter.'</p>';
echo '<ul style="list-style-type: none;>"';
for ($x = 0; $x < $limit; $x++) {
    $title = str_replace(' & ', ' &amp; ', $feed[$x]['title']);

    echo '<li>';
    echo '<a href="" title="'.$title.'" target="_blank">'.$title.'</a>';
    echo '</li>';
}
echo '</ul>';

?>

Answer 1

Your foreach loop that determines the first letter of the title is outside the for loop that actually prints it. Therefore, you are always going to output the last letter of the foreach loop.

Move that part inside the for loop, something like

$limit = 3000;
$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 '<p>'.$firstLetter.'</p>';
        echo '<ul style="list-style-type: none;>"';
        $previous = $firstLetter;
        $count_firstletters ++;
    }
    $title = str_replace(' & ', ' &amp; ', $feed[$x]['title']);

    echo '<li>';
    echo '<a href="" title="'.$title.'" target="_blank">'.$title.'</a>';
    echo '</li>';
}
echo '</ul>';  // Close the last UL