Php Programming

A class is a blueprint for creating objects. It defines properties (variables) and methods (functions) that the objects will have.
class User { public string $name; }

public – accessible from anywhere.
protected – accessible within the class and its subclasses.
private – accessible only within the defining class.
These are known as access modifiers.

Use the new keyword:
$user = new User();
This calls the class constructor (__construct) if one is defined.

__construct() is the constructor that runs automatically when an object is created with new.
public function __construct(public string $name) {}
It initializes object properties.

Inheritance lets a child class extend a parent class using the extends keyword.
class Admin extends User {}
The child inherits all public and protected properties and methods.

An interface defines a contract of methods a class must implement, without providing the method bodies.
interface Loggable { public function log(): void; }
A class uses implements to adopt it.

Yes. A class can implement multiple interfaces separated by commas:
class Report implements Printable, Exportable { }
This provides a form of multiple inheritance for contracts.

A trait is a mechanism for code reuse in single-inheritance languages. It groups methods that can be included in multiple classes.
trait Timestampable { public function now() { return time(); } }

Use the use keyword inside the class body:
class Post { use Timestampable; }
The class then gains all methods defined in the trait.

A fatal error occurs unless you resolve the conflict using insteadof or as:
use TraitA, TraitB { TraitA::log insteadof TraitB; }

Namespaces organize code and prevent name collisions between classes, functions, and constants.
namespace App\Models;
They act like virtual directories for your code.

Use the use statement at the top of the file:
use App\Models\User;
You can also alias it: use App\Models\User as AppUser;