How to get names of all the subfolders and files present in a directory using PHP?

Given the path of the folder and the task is to print the names of subfolders and files present inside them.

Explanation: In our PHP code, initially, it is checked whether provided path or filename is a directory or not using the is_dir() function. Now, we open the directory using opendir() function and then check whether it is getting opened or has some errors. Then we use a while loop to get the names of all the subfolders, as well as files, present inside the directory with the help of readdir() function. Now we are going inside each subfolder and reading the names of all the files present inside them following a similar procedure.

Folder Structure:

Code:
Note: This Code have been saved as PHP file and accessed through wampserver

php

<?php
$gfg_folderpath = "GeeksForGeeks/";
// CHECKING WHETHER PATH IS A DIRECTORY OR NOT
if (is_dir($gfg_folderpath)) {
    // GETTING INTO DIRECTORY
    $files = opendir($gfg_folderpath); {
        // CHECKING FOR SMOOTH OPENING OF DIRECTORY
        if ($files) {
            //READING NAMES OF EACH ELEMENT INSIDE THE DIRECTORY
            while (($gfg_subfolder = readdir($files)) !== FALSE) {
                // CHECKING FOR FILENAME ERRORS
             if ($gfg_subfolder != '.' && $gfg_subfolder != '..') {
                    echo "SUBFOLDER--" .$gfg_subfolder . "<br>
                    "."Files in ".$gfg_subfolder."--<br>";
                     
                $dirpath = "GeeksForGeeks/" . $gfg_subfolder . "/";
                    // GETTING INSIDE EACH SUBFOLDERS
                    if (is_dir($dirpath)) {
                        $file = opendir($dirpath); {
                            if ($file) {
                //READING NAMES OF EACH FILE INSIDE SUBFOLDERS
               while (($gfg_filename = readdir($file)) !== FALSE) {
                if ($gfg_filename != '.' && $gfg_filename != '..') {
                        echo $gfg_filename . "<br>";
                           }
                         }
                      }
                   }
               }
                    echo "<br>";
                }
            }
        }
    }
}
?>
<!DOCTYPE html>
<html>
<head>
  <title>What's there in GeeksForGeeks </title>
</head>
<body>
</body>
</html>