How can the use of classes and magic methods in PHP improve code readability and maintainability in complex projects like a calculator application?

Using classes and magic methods in PHP can improve code readability and maintainability in complex projects like a calculator application by encapsulating related functionality into classes, making the code easier to understand and manage. Magic methods like __construct, __get, and __invoke can help streamline the code by providing predefined behaviors for common operations, reducing the need for repetitive code.

class Calculator {
    private $result;

    public function __construct() {
        $this->result = 0;
    }

    public function add($num) {
        $this->result += $num;
    }

    public function subtract($num) {
        $this->result -= $num;
    }

    public function multiply($num) {
        $this->result *= $num;
    }

    public function getResult() {
        return $this->result;
    }
}

$calc = new Calculator();
$calc->add(5);
$calc->subtract(3);
$calc->multiply(2);

echo $calc->getResult(); // Output: 4