PHP对象的动态命名

class MyClass
{
    public function sayHello()
    {
        echo "Hello!";
    }
}

class_alias('MyClass', 'MyAlias');

$obj = new MyAlias();
$obj->sayHello(); // 输出 "Hello!"

class MyClass
{
    public function sayHello()
    {
        echo "Hello!";
    }
}

$reflection = new ReflectionClass('MyClass');
$className = $reflection->getName();

$obj = new $className();
$obj->sayHello(); // 输出 "Hello!"

class MyClass
{
    public function sayHello()
    {
        echo "Hello!";
    }
}

$className = 'MyClass';
eval("\$obj = new $className();");
$obj->sayHello(); // 输出 "Hello!"