Local and global variable in method's body

variables_into_methods.rb

def method(arg)
	#<<arg>> is not a local copy of global variable - <<string>> and <<arg>> are the same object.
	arg.upcase!
	arg.object_id	#We will return object_id to see if it's true
end

string = 'John'
id = string.object_id
id2 = method(string)
id == id2	#=> true
string		#=> 'JOHN'