PHP — Classes and Objects

Basic anonymous class

<?php
$obj = new class {
    public function greet(): string {
        return "Hello from anonymous class!";
    }
};

echo $obj->greet();
?>

With constructor

<?php
$obj = new class("Alice", 30) {
    public function __construct(
        private string $name,
        private int $age
    ) {}

    public function getInfo(): string {
        return "{$this->name} is {$this->age}";
    }
};

echo $obj->getInfo(); // Alice is 30
?>

Implementing interface

<?php
interface Logger {
    public function log(string $message): void;
}

$logger = new class implements Logger {
    public function log(string $message): void {
        echo "[LOG] $message\n";
    }
};

$logger->log("Application started");
?>

In arrays

<?php
$handlers = [
    'success' => new class {
        public function handle(): void {
            echo "Success!\n";
        }
    },
    'error' => new class {
        public function handle(): void {
            echo "Error!\n";
        }
    },
];

$handlers['success']->handle();
?>

Mini Practice

Write PHP code that:

1. Creates an anonymous class
2. Passes constructor arguments
3. Implements an interface
4. Uses anonymous classes in arrays

Up Next

In the next lesson, you'll learn about Enums — enumerations in PHP 8.1+.