Passing code as function arguments

Question

I was reading a textbook and I was wondering how come the argument we pass to the function is neither a primitive or an user-defined instance of a class.

SwingU         


        

Answer 1

I was wondering how come the argument we pass to the function is neither a primitive or an user-defined instance of a class.

It is an instance of a user-defined class. The only difference is that this class does not have a name ^*.

It is a real instance of a class, though - it can do most of the things a named class can do. Among other things, it can provide implementations of methods of its base class or an interface, which is what is used to pass "a piece of executable code" to a method.

^* At least, not a user-visible one: Java compiler does assign each anonymous class an internal name, which usually contains a dollar sign.