PHP101 – OOP ขั้นสูง (Advanced OOP)

<?php

  namespace MyProject\Database;

  class Connection {
    public function connect() {
      return "Connected to MyProject Database";
    }
  }

  namespace AnotherProject\Database;

  class Connection {
    public function connect() {
      return "Connected to AnotherProject Database";
    }
  }

  use MyProject\Database\Connection as MyConnection;
  use AnotherProject\Database\Connection as AnotherConnection;

  $myConn = new MyConnection();
  echo $myConn->connect() . "<br>"; // Output: Connected to MyProject Database

  $anotherConn = new AnotherConnection();
  echo $anotherConn->connect(); // Output: Connected to AnotherProject Database

?>

<?php

  spl_autoload_register(function ($className) {
    $path = str_replace('\\', '/', $className) . '.php';
    if (file_exists($path)) {
      require $path;
    }
  });

  // สมมติว่ามีคลาส MyProject\Services\UserService อยู่ในไฟล์ MyProject/Services/UserService.php
  $userService = new \MyProject\Services\UserService();
  // PHP จะพยายามโหลดไฟล์ MyProject/Services/UserService.php โดยอัตโนมัติ

?>

<?php

  class Counter {
    public static $count = 0;

    public static function increment() {
      self::$count++;
    }
  }

  Counter::increment();
  Counter::increment();
  echo "Count is: " . Counter::$count; // Output: Count is: 2

?>

<?php

  class MathConstants {
    const PI = 3.14159;
    const E = 2.71828;
  }

  echo "ค่า PI คือ: " . MathConstants::PI . "<br>";
  echo "ค่า E คือ: " . MathConstants::E;

?>

<?php

  abstract class Shape {
    abstract public function area();
    public function displayArea() {
      echo "พื้นที่คือ: " . $this->area() . "<br>";
    }
  }

  class Circle extends Shape {
    private $radius;

    public function __construct($radius) {
      $this->radius = $radius;
    }

    public function area() {
      return pi() * $this->radius * $this->radius;
    }
  }

  $circle = new Circle(5);
  $circle->displayArea(); // Output: พื้นที่คือ: 78.539816339745

?>

<?php

  interface LoggerInterface {
    public function log($message);
  }

  class FileLogger implements LoggerInterface {
    private $filename;

    public function __construct($filename) {
      $this->filename = $filename;
    }

    public function log($message) {
      file_put_contents($this->filename, $message . "\n", FILE_APPEND);
    }
  }

  class DatabaseLogger implements LoggerInterface {
    public function log($message) {
      // โค้ดสำหรับบันทึกลงฐานข้อมูล
      echo "Logged to database: " . $message . "<br>";
    }
  }

  $fileLogger = new FileLogger("app.log");
  $fileLogger->log("Application started");

  $dbLogger = new DatabaseLogger();
  $dbLogger->log("User logged in");

?>

<?php

  trait Loggable {
    public function logMessage($message) {
      echo "Logging: " . $message . "<br>";
    }
  }

  class User {
    use Loggable;

    public $name;

    public function __construct($name) {
      $this->name = $name;
      $this->logMessage("User " . $name . " created");
    }
  }

  class Product {
    use Loggable;

    public $title;

    public function __construct($title) {
      $this->title = $title;
      $this->logMessage("Product " . $title . " added");
    }
  }

  $user = new User("Alice");
  $product = new Product("Laptop");

?>

<?php

  class StringBuilder {
    private $string = "";

    public function append($str) {
      $this->string .= $str;
      return $this;
    }

    public function toUpper() {
      $this->string = strtoupper($this->string);
      return $this;
    }

    public function get() {
      return $this->string;
    }
  }

  $builder = new StringBuilder();
  $result = $builder->append("hello")->append(" world")->toUpper()->get();
  echo $result; // Output: HELLO WORLD

?>