stdClass and objects

stdClass is not the base class of all PHP classes.

Unlike other languages that have classes and objects, all PHP classes are independent of each other apart from classes they extend.

This means that you can’t used stdClass as a type hint for a function that takes any class.

Example that will not work:

function foo(stdClass $bar) {
    // ...
}

PHP 7.2 introduced the object type hint which can be used for this purpose.

https://stackoverflow.com/questions/7839059/type-hinting-for-any-object