For example, is it possible to write code like this:
int $x = 6; str $y = \"hello world\"; bool $z = false; MyObject $foo = new MyObject();
No. That syntax will not work.
You could, theoretically, come up with a system of objects that enforced their own sort of strict typing, but it wouldn't perform and ...why would you want to, anyway?
If you need strict typing, use a strictly typed language.