accessing static methods using a variable class name (PHP)

问题

I am trying to access a static method, but using a variable as the class name. Is this possible? I seem to be having issues with it. I want to be able to do something like this:

class foo {
    public static function bar() {
        echo 'test';
    }
}

$variable_class_name = 'foo';
$variable_class_name::bar();

And I want to be able to do similar using static variables as well.

回答1:

That syntax is only supported in PHP 5.3 and later. Previous versions don't understand that syntax, hence your parse error (T_PAAMAYIM_NEKUDOTAYIM refers to the :: operator).

In previous versions you can try call_user_func(), passing it an array containing the class name and its method name:

$variable_class_name = 'foo';
call_user_func(array($variable_class_name, 'bar'));

回答2:

You can use reflection for PHP 5.1 and above:

class foo {
    public static $bar = 'foobar';
}

$class = 'foo';
$reflector = new ReflectionClass($class);
echo $reflector->getStaticPropertyValue('bar');

> foobar

来源：https://stackoverflow.com/questions/5059957/accessing-static-methods-using-a-variable-class-name-php