了解 PHP 元编程：动态代码操作

<?phpclass dynamicclass {    private $data = [];    // magic method to handle dynamic property setting    public function __set($name, $value) {        echo "setting '$name' to '$value'.";        $this->data[$name] = $value;    }    // magic method to handle dynamic property getting    public function __get($name) {        if (array_key_exists($name, $this->data)) {            echo "getting '$name'.";            return $this->data[$name];        }        echo "property '$name' not set.";        return null;    }    // magic method to handle dynamic method calls    public function __call($name, $arguments) {        echo "calling method '$name' with arguments: " . implode(', ', $arguments) . "";        return null;    }}// usage example$obj = new dynamicclass();// setting properties dynamically$obj->name = "metaprogramming";$obj->type = "php";// getting properties dynamicallyecho $obj->name . "";  // outputs: metaprogrammingecho $obj->type . "";  // outputs: php// calling a dynamic method$obj->dynamicmethod("arg1", "arg2");

setting 'name' to 'metaprogramming'.setting 'type' to 'php'.getting 'name'.metaprogramminggetting 'type'.phpcalling method 'dynamicmethod' with arguments: arg1, arg2

<?phpclass exampleclass {    public $name;    public $type;    public function __construct($name, $type) {        $this->name = $name;        $this->type = $type;    }    public function sayhello() {        echo "hello from $this->name, a $this->type example!";    }}function reflectonclass($classname) {    // reflecting on the class    $reflector = new reflectionclass($classname);    echo "class: " . $reflector->getname() . "";    // reflecting on the class properties    echo "properties: ";    foreach ($reflector->getproperties() as $property) {        echo "- " . $property->getname() . "";    }    // reflecting on the class methods    echo "methods: ";    foreach ($reflector->getmethods() as $method) {        echo "- " . $method->getname() . "";    }}// usage example$example = new exampleclass("metaprogramming", "php");$example->sayhello();  // outputs: hello from metaprogramming, a php example!// reflecting on the exampleclassreflectonclass('exampleclass');

hello from metaprogramming, a php example!class: exampleclassproperties: - name- typemethods: - __construct- sayhello

<?phpclass calculator {    public function add($a, $b) {        return $a + $b;    }    public function multiply($a, $b) {        return $a * $b;    }}function dynamicinvoke($object, $methodname, $args) {    try {        $method = new reflectionmethod($object, $methodname);        return $method->invokeargs($object, $args);    } catch (reflectionexception $e) {        echo "method not found: " . $e->getmessage() . "";    }}// example usage$calc = new calculator();// dynamically invoke 'add' method$result1 = dynamicinvoke($calc, 'add', [2, 3]);echo "addition result: " . $result1 . "";  // outputs: 5// dynamically invoke 'multiply' method$result2 = dynamicinvoke($calc, 'multiply', [3, 4]);echo "multiplication result: " . $result2 . "";  // outputs: 12// attempt to invoke a non-existent methoddynamicinvoke($calc, 'subtract', [5, 2]);

Addition Result: 5Multiplication Result: 12Method not found: Method Calculator::subtract() does not exist