The FilesystemIterator::key() function is an inbuilt function in PHP which is used to retrieve the key for the current file.
Syntax:
string FilesystemIterator::key( void )
Parameters: This function does not accept any parameters.
Return Value: This function returns the pathname or filename depending on the set flags.
Below programs illustrate the FilesystemIterator::key() function in PHP:
Program 1:
<?php   // Create new file system iterator $fileItr = new FilesystemIterator(dirname(__FILE__),         FilesystemIterator::KEY_AS_FILENAME);   // Loop runs for each element of file iterator foreach($fileItr as $it) {       // Display the key     echo $fileItr->key() . "<br>"; }   ?> |
Output:
applications.html bitnami.css dashboard favicon.ico gfg.php img index.php webalizer xampp
Program 2:
<?php   // Create new file system iterator $fileItr = new FilesystemIterator(dirname(__FILE__),         FilesystemIterator::KEY_AS_FILENAME);   // Loop runs while file iterator is valid while ($fileItr->valid()) {       // Check for non directory files     if (!$fileItr->isDir()) {           // Display the key         echo $fileItr->key() . "<br>";     }       // Move to the next element     $fileItr->next(); }   ?> |
Output:
applications.html bitnami.css favicon.ico gfg.php index.php
Note: The output of this function depends on the content of server folder.
Reference: https://www.php.net/manual/en/filesystemiterator.key.php
