<?php
/* ---------------- ARRAYS ---------------- */

// Indexed Array
$fruits = ["Apple", "Banana", "Mango"];
echo $fruits[0] . "<br>";

// Associative Array
$user = ["name" => "Tanishq", "age" => 21];
echo $user["name"] . "<br>";

// Multidimensional Array
$students = [["John", 90], ["Aman", 85]];
echo $students[0][0] . "<br>";

// Array Merge
$a = ["Red", "Green"];
$b = ["Blue", "Yellow"];
$merged = array_merge($a, $b);
print_r($merged);
echo "<br><br>";



/* ---------------- FILE OPERATIONS ---------------- */

$filename = "demo.txt";

// file_exists()
echo file_exists($filename) ? "File exists<br>" : "File not found<br>";

// fopen() + fwrite()
$file = fopen($filename, "w");
fwrite($file, "Hello PHP!");
fclose($file);

// fopen() + fread()
$file = fopen($filename, "r");
echo fread($file, filesize($filename)) . "<br>";
fclose($file);

// unlink()  // delete file if needed
// unlink($filename);



/* ---------------- FILE UPLOAD ---------------- */
// HTML form needed:
// <form method="POST" enctype="multipart/form-data"><input type="file" name="myfile"><button>Upload</button></form>

if ($_FILES) {
    if ($_FILES["myfile"]["error"] == 0) {
        move_uploaded_file($_FILES["myfile"]["tmp_name"], "uploads/" . $_FILES["myfile"]["name"]);
        echo "File uploaded!<br>";
    }
}



/* ---------------- DIRECTORY OPERATIONS ---------------- */

$dir = "myfolder";

// Check directory exists
if (!is_dir($dir)) {
    mkdir($dir); // create directory
    echo "Directory created<br>";
} else {
    echo "Directory exists<br>";
}

// Reading directory using scandir()
$files = scandir($dir);
echo "scandir(): ";
print_r($files);
echo "<br>";

// Reading directory using opendir()
if ($handle = opendir($dir)) {
    echo "Files inside using opendir(): ";
    while (($file = readdir($handle)) !== false) {
        echo $file . " ";
    }
    closedir($handle);
    echo "<br>";
}

// Delete directory (only if empty)
// rmdir($dir);
?>