It’s good to follow Ruby convetions while writing Ruby programs. In this short tutorial I will a cover a few rules about naming variables, methods, classes and modules in Ruby.

Global Variables: Golabal variables in Ruby start with a dollar sign: $

$i_am_a_global_variable

Class Variables: Class variables are prefixed with two “at” signs: @@

@@i_am_a_class_variable

Instance Variables: Instance variable starts with an “at” sign: @

@i_am_an_instance_variable

Local Varaibles: Local variables are in lowercase letters.

i_am_a_local_variable

Constants: Constants start with an uppercase letter.

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Class Names: Class names begin with an uppercase letter.

class String 
  ...
end
class ReadOnlyAssociation
  ...
end

Module Names: Module names start with an uppercase letter like class names.

module Kernel 
  ...
end
module ActiveRecord
  ...
end

Method names and parameters: In Ruby, method names and parameters should start with smallcase letter. If method name or parameters has includes than one words, you should separate them using underscores.

def my_method(param1, param2)
  ...
end

Resources:

• Programming Ruby – The Pragmatic Programmer’s Guide