A copy of php programmer interview questions

/**
* Traverse the directory and store the results in an array. Supports php4 and above. After php5, the scandir() function can be used to replace the while loop.
* @param string $dir
* @return array
*/
my_scandir($dir)
{
$files = array();
if ( $handle = opendir($dir) )
{
while ( ($file = readdir($handle)) !== false )
{
if ( $file != ".." && $file != "." )
{
if ( is_dir($dir . "/" . $file) )
{
$files[$file] = rec_scandir($dir . "/" . $file);
}
else
{
$files[] = $file;
}
}
}
closedir($handle );
return $files;
}
}

Briefly describe the implementation principle of unlimited classification in the forum. Design a web page so that when it is opened, a full-screen window pops up with a text box and a button. After the user enters information in the text box and clicks the button, the window can be closed, while the entered information is displayed on the main web page.