PHP Cheat Sheet

<?php
// Standard PHP tag
 
echo "Hello World";
 
// Short echo tag (always available)
<?= "Hello World" ?>
 
// Inline PHP
<?php echo "Hello"; ?>

<?php
// Single line comment
 
# Single line comment (style Unix)
 
/*
 * Multi-line comment
 * Bisa banyak baris
 */
 
/**
 * DocBlock comment
 * Buat dokumentasi function/class
 */

<?php
// Echo - bisa multiple parameters
echo "Hello", " ", "World";
echo "Hello World";
 
// Print - cuma satu parameter, return value
print "Hello World";
 
// Print_r - buat debug array/object
print_r($array);
 
// Var_dump - detailed info dengan type

<?php
// Variable diawali $
$name = "Budi";
$age = 25;
$price = 99.99;
 
// Variable variables
$var = "hello";
$$var = "world";
echo

<?php
// String
$name = "Budi";
$greeting = 'Hello';
 
// Integer
$age = 25;
$hex = 0x1A; // Hexadecimal
$binary =

<?php
// Check types
is_string($var);
is_int($var);
is_float($var);
is_bool($var);
is_array($var);
is_object($var);
is_null($var);
is_numeric($var);
 
// Get type
gettype($var);

<?php
// Concatenation
$fullName = $firstName . " " . $lastName;
$text = "Hello" . " " . "World";
 
// String interpolation (double quotes)
$name = "Budi";
echo

<?php
$str = "Hello World";
 
// Length
strlen($str); // 11
 
// Position
strpos($str, "World"); // 6
strrpos

<?php
// Indexed array
$fruits = ["Apple", "Banana", "Orange"];
$numbers = array(1, 2, 3, 4, 5);
 
// Associative array

<?php
$arr = [1, 2, 3, 4, 

<?php
if ($age >= 18) {
  echo "Dewasa";
} elseif ($age >= 13) {
  echo "Remaja";
} else {
  echo "Anak-anak";
}

<?php
switch ($day) {
  case 'Monday':
    echo "Senin";
    break;
  case 'Friday':
    echo "Jumat";
    break;
  default:
    echo "Hari lain";

<?php
// For loop
for ($i = 0; $i < 10; $i++) {
  echo $i;
}
 
// While loop
$i = 0;
while ($i <

<?php
// Basic function
function greet($name) {
  return "Hello, $name";
}
 
// Default parameters
function greet($name = "Guest") {
  return "Hello, $name

<?php
// Short syntax
$double = fn($n) => $n * 2;
 
// Auto-capture variables
$multiplier = 3;
$triple = fn($n) => $n * $multiplier;
 
// With array functions
array_map(fn($n) => $n 

<?php
$func = 'greet';
$func('Budi'); // Call greet('Budi')
 
// Anonymous function
$greet = function($name) {
  return "Hello, $name";
};
 
// Closure with use
$multiplier =

<?php
class Person {
  // Properties
  public string $name;
  private int $age;
  protected string $email;
 
  // Constructor
  public function __construct(

<?php
class User {
  // Property dengan hooks
  public string $name {
    // Get hook
    get => strtoupper($this->name);
    // Set hook
    set => ucfirst($value);
  }

<?php
class Animal {
  protected string $name;
 
  public function __construct(string $name) {
    $this->name = $name;
  }
 
  public function makeSound

<?php
// Interface
interface Drivable {
  public function drive(): void;
  public function stop(): void;
}
 
class Car

<?php
abstract class Shape {
  abstract public function area(): float;
 
  public function describe(): string {
    return "This is a shape";
  }

<?php
class Status {
  public const string ACTIVE = 'active';
  public const string INACTIVE = 'inactive';
  public const int MAX_RETRY = 3;
}

<?php
class User {
  // Public read, private write
  public private(set) string $username;
 
  public function __construct(string $username) {
    $this->username = $username;
  }
}
 
$user 

<?php
// Tanpa null safe
$country = null;
if ($user !== null) {
  $country = $user->getAddress()?->getCountry();
}
 
// Dengan null safe
$country = $user?->

<?php
function createUser(
  string $name,
  int $age,
  string $email = '',
  bool $active = true
) {
  // ...
}
 
// Skip parameters
createUser(
  name

<?php
$result = match($status) {
  'pending' => 'Waiting',
  'approved', 'confirmed' => 'Accepted',
  'rejected' => 'Denied',
  default => 'Unknown'
};
 
// Dengan kondisi

<?php
#[Route('/api/users')]
class UserController {
  #[Get]
  #[Cached(seconds: 3600)]
  public function index() {
    // ...
  }
}

<?php
enum Status {
  case Pending;
  case Approved;
  case Rejected;
}
 
enum Status: string {
  case Pending =

<?php
class User {
  public function __construct(
    public readonly string $id,
    public readonly string $name,
  ) {}
}
 
$user = new User('123', 'Budi'

<?php
readonly class Config {
  public function __construct(
    public string $apiKey,
    public string $apiUrl,
  ) {}
}

<?php
try {
  // Code yang mungkin error
  $result = riskyOperation();
} catch (Exception $e) {
  // Handle error
  echo "Error: " . $e->getMessage();
} finally

<?php
class UserNotFoundException extends Exception {}
 
function findUser($id) {
  if (!userExists($id)) {
    throw new UserNotFoundException("User not found");
  }
  return getUser($id);

<?php
#[\Deprecated(
  message: "Use newMethod() instead",
  since: "1.5.0"
)]
function oldMethod() {
  // ...
}

<?php
// Read entire file
$content = file_get_contents('file.txt');
 
// Read as array
$lines = file('file.txt');
 
// Read with fopen
$file = fopen('file.txt', 'r');

<?php
// Write string to file
file_put_contents('file.txt', 'Hello World');
 
// Append to file
file_put_contents('file.txt', 'More content', FILE_APPEND);
 
// Write with fopen
$file = fopen('file.txt', 

<?php
// Check existence
file_exists('file.txt');
is_file('file.txt');
is_dir('directory');
 
// File info
filesize('file.txt');
filemtime('file.txt'); 

<?php
try {
  $pdo = new PDO(
    'mysql:host=localhost;dbname=mydb',
    'username',
    'password',
    [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]
  );
} 

<?php
// Select
$stmt = $pdo->query("SELECT * FROM users");
$users = $stmt->fetchAll(

{
  "require": {
    "monolog/monolog": "^3.0"
  },
  "autoload": {
    "psr-4": {
      "App\\": "src/"
    }
  }
}

# Install dependencies
composer install
 
# Update dependencies
composer update
 
# Add package
composer require vendor/package
 
# Remove package
composer remove vendor/package
 
# Dump autoload
composer dump-autoload

<?php
require 'vendor/autoload.php';
 
use App\Models\User;
use Monolog\Logger;
 
$user = new User();
$logger = new Logger('app');

<?php
// Always use type declarations
function processUser(User $user): bool {
  // ...
}
 
// Strict types (recommended)
declare(strict_types=1);

<?php
// Enable error reporting di development
error_reporting(E_ALL);
ini_set('display_errors', 1);
 
// Disable di production
error_reporting(0);
ini_set('display_errors', 0);

<?php
// Prevent XSS
echo htmlspecialchars($userInput, ENT_QUOTES, 'UTF-8');
 
// Prevent SQL injection
$stmt = $pdo->prepare("SELECT * FROM users WHERE id =