class vs Class.new, module vs Module.new

Question

What is difference between class and Class.new & module and Module.new?

I know that:

1. C

Answer 1

Class.new returns an object. class A returns nil. Same goes for modules.

That's wrong. A class/module definition returns the value of the last expression evaluated inside of the class/module body:

class Foo
  42
end
# => 42

Typically, the last expression evaluated inside of a class/module body will be a method definition expression, which in current versions of Ruby returns a Symbol denoting the name of the method:

class Foo
  def bar; end
end
# => :bar

In older versions of Ruby, the return value of a method definition expression was implementation-defined. Rubinius returned a CompiledMethod object for the method in question, whereas YARV and most others simply returned nil.