By default, camelize converts strings to UpperCamelCase. If the argument to camelize is set to ":lower" then camelize produces lowerCamelCase.

camelize will also convert ’/’ to ’::’ which is useful for converting paths to namespaces

Examples

"active_record".camelize #=> "ActiveRecord"
"active_record".camelize(:lower) #=> "activeRecord"
"active_record/errors".camelize #=> "ActiveRecord::Errors"
"active_record/errors".camelize(:lower) #=> "activeRecord::Errors"

Source Code

# File active_support/inflector.rb, line 147
def camelize(lower_case_and_underscored_word, first_letter_in_uppercase = true)
  if first_letter_in_uppercase
    lower_case_and_underscored_word.to_s.gsub(/\/(.?)/) { "::#{$1.upcase}" }.gsub(/(?:^|_)(.)/) { $1.upcase }
  else
    lower_case_and_underscored_word.first + camelize(lower_case_and_underscored_word)[1..-1]
  end
end