PHP

<?php
echo "Apache version: " . apache_get_version() . "<br>";
$mods = apache_get_modules();
echo "Loaded modules: " . count($mods) . "<br>";
echo "mod_rewrite loaded? " . (in_array("mod_rewrite", $mods) ? "yes" : "no") . "<br>";
echo "<b>Some request headers sent by the browser:</b><br>";
$h = apache_request_headers();
foreach (["Host", "Accept-Language", "Connection"] as $k) {
    echo "$k: " . ($h[$k] ?? "-") . "<br>";
}
?>

<?php
echo "<pre>";
print_r(range(0, 20, 5));
print_r(array_fill(5, 3, "x"));
print_r(array_combine(["a", "b", "c"], [1, 2, 3]));
$city = "Bhopal"; $state = "MP";
print_r(compact("city", "state"));
print_r(array_count_values(["php", "sql", "php", "js", "php"]));
$ages = ["Peter" => 32, "Asha" => 21];
var_dump(array_key_exists("Asha", $ages));
echo "array_search(21) = " . array_search(21, $ages) . "\n";
echo "array_keys: " . implode(", ", array_keys($ages)) . "\n";
echo "array_key_last: " . array_key_last($ages) . "\n";
echo "</pre>";
?>

<?php
$stack = ["php", "mysql"];
echo "array_push returns " . array_push($stack, "html", "css") . ": " . implode(", ", $stack) . "<br>";
echo "array_pop removed '" . array_pop($stack) . "': " . implode(", ", $stack) . "<br>";
array_unshift($stack, "linux");
echo "after array_unshift: " . implode(", ", $stack) . "<br>";
echo "array_shift removed '" . array_shift($stack) . "'<br>";
echo "array_merge: " . implode(", ", array_merge([1, 2], [3, 4], [5])) . "<br>";
$a = ["x" => 1, "y" => 2];
$b = ["y" => 20, "z" => 30];
echo "array_merge with keys: " . json_encode(array_merge($a, $b)) . "<br>";
echo "array_merge_recursive: " . json_encode(array_merge_recursive($a, $b)) . "<br>";
$n = [10, 20, 30, 40, 50];
echo "array_slice(1, 3): " . implode(", ", array_slice($n, 1, 3)) . "<br>";
array_splice($n, 1, 2, ["A", "B", "C"]);
echo "after array_splice: " . implode(", ", $n) . "<br>";
echo "array_pad: " . implode(", ", array_pad([1, 2], 5, 0)) . "<br>";
echo "array_chunk: " . json_encode(array_chunk([1, 2, 3, 4, 5], 2)) . "<br>";
echo "array_flip: " . json_encode(array_flip(["a" => 1, "b" => 2])) . "<br>";
echo "array_unique: " . implode(", ", array_unique([3, 1, 3, 2, 1])) . "<br>";
echo "array_reverse: " . implode(", ", array_reverse([1, 2, 3]));
?>

<?php
$batchA = ["Asha", "Ravi", "Neha", "John"];
$batchB = ["Ravi", "John", "Kiran"];
echo "Only in A (array_diff): " . implode(", ", array_diff($batchA, $batchB)) . "<br>";
echo "In both (array_intersect): " . implode(", ", array_intersect($batchA, $batchB)) . "<br>";
$x = ["a" => "green", "b" => "brown", "c" => "blue", "red"];
$y = ["a" => "green", "yellow", "red"];
echo "array_diff_assoc: " . json_encode(array_diff_assoc($x, $y)) . "<br>";
echo "array_intersect_assoc: " . json_encode(array_intersect_assoc($x, $y)) . "<br>";
echo "array_udiff (case-insensitive): " .
     implode(", ", array_udiff(["PHP", "Java"], ["php"], 'strcasecmp'));
?>

<?php
$prices = [120, 450, 80, 999];
echo "array_map (+18% GST): " . implode(", ", array_map(fn($p) => $p * 1.18, $prices)) . "<br>";
echo "array_filter (> 100): " . implode(", ", array_filter($prices, fn($p) => $p > 100)) . "<br>";
echo "array_reduce (total): " . array_reduce($prices, fn($c, $p) => $c + $p, 0) . "<br>";
echo "array_sum: " . array_sum($prices) . ", array_product([2,3,4]): " . array_product([2, 3, 4]) . "<br>";
$marks = ["Asha" => 82, "Ravi" => 64];
array_walk($marks, function (&$m, $name) { $m = "$name scored $m"; });
echo "array_walk: " . implode("; ", $marks) . "<br>";
$students = [
    ["id" => 1, "name" => "Asha"],
    ["id" => 2, "name" => "Ravi"],
];
echo "array_column: " . json_encode(array_column($students, "name", "id"));
?>

<?php
$files = ["img12.png", "img10.png", "IMG2.png", "img1.png"];
$a = $files; sort($a);
echo "sort: " . implode(", ", $a) . "<br>";
$b = $files; natsort($b);
echo "natsort: " . implode(", ", $b) . "<br>";
$c = $files; natcasesort($c);
echo "natcasesort: " . implode(", ", $c) . "<br>";
$stock = ["pen" => 40, "book" => 15, "bag" => 25];
arsort($stock);
echo "arsort: " . json_encode($stock) . "<br>";
krsort($stock);
echo "krsort: " . json_encode($stock) . "<br>";
$names = ["Ravi", "Asha", "Neha"];
$marks = [64, 82, 82];
array_multisort($marks, SORT_DESC, $names, SORT_ASC);
echo "array_multisort: " . implode(", ", array_map(fn($n, $m) => "$n($m)", $names, $marks));
?>

<?php
$days = ["Mon", "Tue", "Wed", "Thu"];
echo "current: " . current($days) . "<br>";
echo "next: " . next($days) . "<br>";
echo "next: " . next($days) . ", key: " . key($days) . "<br>";
echo "prev: " . prev($days) . "<br>";
echo "end: " . end($days) . "<br>";
echo "reset: " . reset($days);
?>