Ruby has two types of comments: inline and block.
Inline comments start with the
# character and continue until the end of the line:
# On a separate line class Foo # or at the end of the line # can be indented def bar end end
Block comments start with
=begin and end with
=end. Each should start on a separate line.
=begin This is commented out =end class Foo end =begin some_tag this works, too =end
=end can not be indented, so this is a syntax error:
class Foo =begin Will not work =end end
The Ruby standard library includes the RDoc tool for generating documentation from code. RDoc format is “unobtrusive” (plain text) documentation. Ruby gem YARD is also frequently used to generate documentation, providing a more strict format allowing rendering of “tags” (param types, return type, examples and so on).