what does ::Class in ruby do?

Question

Possible Duplicate:
What is Ruby’s double-colon (::) all about?

pardon for my laziness. I tried to guess. I am not sure what the double '::Logger' does in this case?

https://github.com/wycats/rack-offline/blob/master/lib/rack/offline.rb#L25

it seems like it is initializing the object and assign it on a variable that is not in its scope? line 25 is wrapped by {begin/end} block and gets assigned to @logger

`::Logger` is referencing `Logger` class from top level namespace. — Sergio Tulentsev, Jan 12 '13 at 05:22
[We answered this very question yesterday](http://stackoverflow.com/q/14271860/512904). — Matheus Moreira, Jan 12 '13 at 05:39

score 3 · Accepted Answer · answered Jan 12 '13 at 05:30

Just like a / in a path defines nested directories, :: accesses nested classes.

And also similarly to a leading /, a leading :: means to start at the the very top of the tree. It starts searching for constants at the global scope.

# Bar declared in global scope
class Bar
end

# Foo declared in global scope    
class Foo

  # A different class named Bar declared in the scope of Foo, not global
  class Bar
  end

  Bar   #=> refers to Foo::Bar, that is class Bar declared within Foo
  ::Bar #=> refers to outer global scope class named Bar

end

what does ::Class in ruby do?

1 Answers1