readdir组文件夹的第一个字母

Question

I have a list of folders but want to group them by first letter ie all A folders together, all B folder together etc:

$handle = opendir(".");
$projectContents = '';
while ($file = readdir($handle)) 
{
    if (is_dir($file) && !in_array($file,$projectsListIgnore)) 
    {

$projectContents .= '<li><a href="'.$file.'">'.$file.'</a></li>';

    }
}
closedir($handle);

Output:

<ul>
 $projectContents
</ul>

The above snippet lists them fine from a-2-z but I don't know how to section them off into groups.

The closing and re-opening of </ul><ul> with each new letter section would be enough but again don't kow how to impliment into the current snippet.

Answer 1

Compare the first character of the current file name in the loop with the first character of the previous one, then print the </ul><ul> if they're not the same:

$handle = opendir(".");
$projectContents = '';
$firstLetter = '';
while ($file = readdir($handle)) 
{
    if (is_dir($file) && !in_array($file,$projectsListIgnore)) 
    {
        if ($firstLetter != strtoupper($file{0}) && $firstLetter != '')
        {
            $projectContents .= '</ul><ul>';
        }
        $firstLetter = strtoupper($file{0}); // Store the current character for comparison
        $projectContents .= '<li><a href="'.$file.'">'.$file.'</a></li>';

    }
}
closedir($handle);