Question

So, I’m curious as to how Ruby is a fully object oriented language. I stumble over one problem that isn’t really clear to me.

If I define a function as follows

def foo(text)
  print text
end

and I define the function outside of a class, how is this function an object? I realize that I can call

foo.class

And I get NilClass. Does this mean that foo is an instance of NilClass? And if it is, what does it mean exactly when I call

foo "hello world"

If foo is an object, what method am I calling when I make the statement as above. Also, if it an object, does that mean I can modify it and add another method to it (say bar) where I could possibly make the following statment:

foo.bar(some variables)

Sorry, I’m just a little confused on this point. Any clarification is very much appreciated! Thanks!

Answer 1

• User defined global functions (top-level functions) are instance methods of Object (even though the class of self is not Object).
• Top-level methods are always private.