Calculator Class

Calculator.php

<?php
/**
 * Calculator Class
 * @author Jeff Yates <hello+gist@jeffyates.com>
 */
class Calculator
{
    public function __call($method, $args)
    {
        $methods = array(
            'add' => '+',
            'subtract' => '-',
            'multiply' => '*',
            'divide' => '/'
        );

        try {
            if (array_key_exists($method, $methods) === false) {
                throw new Exception("Invalid operation");
            }

            $calculate = implode($methods[$method], $args);
            if ($method === 'divide' && preg_match('/0$/i', $calculate) === 1) {
                throw new Exception("Division by zero");
            }

            return eval("return $calculate;");
        } catch (Exception $e) {
            return 0;
        }
    }
}

// Examples
$calc = new Calculator;
var_dump($calc->add(1,2,3,4,5));
var_dump($calc->subtract(5,4));
var_dump($calc->multiply(4,3,2));
var_dump($calc->divide(4,0));
var_dump($calc->divide(4,1));
var_dump($calc->add($calc->subtract(10,1), $calc->multiply(3,1)));