PHP

<?php
// Variables (weakly typed, dynamic)
$name = "Sufi";
$age = 30;
$price = 9.99;
$active = true;
$nothing = null;

// String operations echo "Hello, $name!"; // interpolation echo 'Hello, ' . $name . '!'; // concatenation echo strlen($name); // 4 echo strtoupper($name); // SUFI echo str_replace('o', '0', $name); // Sufi → Sufi echo sprintf("Price: $%.2f", $price); // Price: $9.99

// Arrays $fruits = ['apple', 'banana', 'cherry']; $person = ['name' => 'Sufi', 'age' => 30]; // associative echo $fruits[0]; // apple echo $person['name']; // Sufi echo count($fruits); // 3 array_push($fruits, 'date'); $sorted = sort($fruits); ```

<?php
// Conditionals
if ($age >= 18) {
    echo "Adult";
} elseif ($age >= 13) {
    echo "Teen";
} else {
    echo "Child";
}

// Match expression (PHP 8+) $status = match($code) { 200 => 'OK', 404 => 'Not Found', 500 => 'Server Error', default => 'Unknown' };

// Loops foreach ($fruits as $index => $fruit) { echo "$index: $fruit "; }

// Functions function calculateTax(float $amount, float $rate = 0.15): float { return $amount * $rate; }

// Arrow functions (PHP 7.4+) $double = fn($x) => $x * 2; $doubled = array_map($double, [1, 2, 3, 4]); // [2, 4, 6, 8]

// Named arguments (PHP 8+) echo implode(separator: ', ', array: $fruits); ```

<?php
abstract class Animal {
    protected string $name;
    private static int $count = 0;

public function __construct(string $name) { $this->name = $name; self::$count++; }

abstract public function speak(): string;

public static function getCount(): int { return self::$count; }

public function __toString(): string { return "Animal({$this->name})"; } }

interface Trainable { public function train(string $command): bool; }

class Dog extends Animal implements Trainable { private array $tricks = [];

public function speak(): string { return "{$this->name} says: Woof!"; }

public function train(string $command): bool { $this->tricks[] = $command; return true; } }

$dog = new Dog("Rex"); echo $dog->speak(); // Rex says: Woof! echo Animal::getCount(); // 1 ```

<?php
// PDO secure database abstraction
$dsn = "mysql:host=localhost;dbname=myapp;charset=utf8mb4";
$pdo = new PDO($dsn, 'username', 'password', [
    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    PDO::ATTR_EMULATE_PREPARES => false,
]);

// Parameterized queries prevent SQL injection $stmt = $pdo->prepare("SELECT * FROM users WHERE email = ? AND active = ?"); $stmt->execute([$email, 1]); $user = $stmt->fetch();

// Named parameters $stmt = $pdo->prepare("INSERT INTO users (name, email, role) VALUES (:name, :email, :role)"); $stmt->execute(['name' => $name, 'email' => $email, 'role' => 'user']); $newId = $pdo->lastInsertId();

// Transaction $pdo->beginTransaction(); try { $pdo->prepare("UPDATE accounts SET balance = balance - ? WHERE id = ?")->execute([$amount, $from]); $pdo->prepare("UPDATE accounts SET balance = balance + ? WHERE id = ?")->execute([$amount, $to]); $pdo->commit(); } catch (Exception $e) { $pdo->rollBack(); throw $e; } ```

<?php
// Eloquent ORM
class User extends Model {
    protected $fillable = ['name', 'email', 'role'];
    protected $hidden = ['password', 'remember_token'];
    protected $casts = ['email_verified_at' => 'datetime'];

public function posts(): HasMany { return $this->hasMany(Post::class); }

public function roles(): BelongsToMany { return $this->belongsToMany(Role::class); } }

// Query builder $users = User::where('active', true) ->where('created_at', '>=', now()->subDays(30)) ->orderBy('name') ->with('posts') // eager load ->paginate(20);

// Routes (web.php) Route::get('/users', [UserController::class, 'index'])->middleware('auth'); Route::resource('/posts', PostController::class);

// Blade template // {{ $user->name }} @foreach($posts as $post) {{ $post->title }} @endforeach

// Artisan commands // php artisan make:model User -mrc (model + migration + resource controller) // php artisan migrate // php artisan queue:work ```

<?php
// PHP 8.x features
// Union types
function process(int|string $input): int|string { ... }

// Nullsafe operator $city = $user?->address?->city;

// Fibers (PHP 8.1) cooperative multitasking $fiber = new Fiber(function(): void { $value = Fiber::suspend('first'); echo "Got: $value "; }); $first = $fiber->start(); // 'first' $fiber->resume('hello'); // Prints: Got: hello

// Security essentials password_hash($password, PASSWORD_ARGON2ID); // hash passwords password_verify($input, $hash); // verify filter_var($email, FILTER_VALIDATE_EMAIL); // validate input htmlspecialchars($output, ENT_QUOTES, 'UTF-8'); // escape output ```