Classes and Objects in PHP with syntax and examples

Classes are templates for creating objects, encapsulating data and behavior. Objects are instances of classes, representing real-world entities.

Class Syntax:


class ClassName {
  // properties
  public $property1;
  protected $property2;
  private $property3;

  // constructor
  public function __construct($arg1, $arg2) {
    $this->property1 = $arg1;
    $this->property2 = $arg2;
  }

  // methods
  public function method1() {
    // code
  }
  protected function method2() {
    // code
  }
  private function method3() {
    // code
  }
}


Constructor Syntax:


public function __construct($arg1, $arg2) {
  // initialization code
}


Example:


class User {
  public $name;
  protected $email;

  public function __construct($name, $email) {
    $this->name = $name;
    $this->email = $email;
  }

  public function sayHello() {
    echo "Hello, my name is $this->name!";
  }
}

$user = new User("Saifosys", "saifosys@gmail.com");
$user->sayHello(); // outputs "Hello, my name is Saifosys!"


Object Properties:

- public: Accessible from anywhere
- protected: Accessible within the class and its descendants
- private: Accessible only within the class

Object Methods:

- public: Callable from anywhere
- protected: Callable within the class and its descendants
- private: Callable only within the class

Constructor Purpose:

- Initializes object properties
- Sets default values
- Performs setup tasks

Best Practices:

1. Use meaningful class and property names
2. Encapsulate data and behavior
3. Use constructors for initialization
4. Validate and sanitize input data
5. Test class functionality thoroughly

By understanding classes and objects in PHP, you can create structured, reusable code and represent real-world entities in your applications.