Converts strings to UpperCamelCase. If the +uppercase_first_letter+ parameter is set to false, then produces lowerCamelCase.

Also converts "/" to "::" which is useful for converting paths to namespaces.

camelize("active_model") # => "ActiveModel" camelize("active_model", false) # => "activeModel" camelize("active_model/errors") # => "ActiveModel::Errors" camelize("active_model/errors", false) # => "activeModel::Errors"

As a rule of thumb you can think of +camelize+ as the inverse of #underscore, though there are cases where that does not hold:

camelize(underscore("SSLError")) # => "SslError"

Creates a class name from a plural table name like Rails does for table names to models. Note that this returns a string and not a Class (To convert to an actual class follow +classify+ with #constantize).

classify("ham_and_eggs") # => "HamAndEgg" classify("posts") # => "Post"

Singular names are not handled correctly:

classify("calculus") # => "Calculus"

Replaces underscores with dashes in the string.

dasherize("puni_puni") # => "puni-puni"

Removes the rightmost segment from the constant expression in the string.

deconstantize("Net::HTTP") # => "Net" deconstantize("::Net::HTTP") # => "::Net" deconstantize("String") # => "" deconstantize("::String") # => "" deconstantize("") # => ""

See also #demodulize.

Removes the module part from the expression in the string.

demodulize("ActiveRecord::CoreExtensions::String::Inflections") # => "Inflections" demodulize("Inflections") # => "Inflections" demodulize("::Inflections") # => "Inflections" demodulize("") # => ""

See also #deconstantize.

Creates a foreign key name from a class name. +separate_class_name_and_id_with_underscore+ sets whether the method should put "_" between the name and "id".

foreign_key("Message") # => "message_id" foreign_key("Message", false) # => "messageid" foreign_key("Admin::Post") # => "post_id"

Tweaks an attribute name for display to end users.

Specifically, performs these transformations:

• Applies human inflection rules to the argument.
• Deletes leading underscores, if any.
• Removes a "_id" suffix if present.
• Replaces underscores with spaces, if any.
• Downcases all words except acronyms.
• Capitalizes the first word.

The capitalization of the first word can be turned off by setting the +:capitalize+ option to false (default is true).

humanize("employee_salary") # => "Employee salary" humanize("author_id") # => "Author" humanize("author_id", capitalize: false) # => "author" humanize("_id") # => "Id"

If "SSL" was defined to be an acronym:

humanize("ssl_error") # => "SSL error"

Yields a singleton instance of Inflector::Inflections so you can specify additional inflector rules. If passed an optional locale, rules for other languages can be specified. If not specified, defaults to :en. Only rules for English are provided.

ActiveSupport::Inflector.inflections(:en) do |inflect| inflect.uncountable 'rails' end

Returns the suffix that should be added to a number to denote the position in an ordered sequence such as 1st, 2nd, 3rd, 4th.

ordinal(1) # => "st" ordinal(2) # => "nd" ordinal(1002) # => "nd" ordinal(1003) # => "rd" ordinal(-11) # => "th" ordinal(-1021) # => "st"

Turns a number into an ordinal string used to denote the position in an ordered sequence such as 1st, 2nd, 3rd, 4th.

ordinalize(1) # => "1st" ordinalize(2) # => "2nd" ordinalize(1002) # => "1002nd" ordinalize(1003) # => "1003rd" ordinalize(-11) # => "-11th" ordinalize(-1021) # => "-1021st"

Returns the plural form of the word in the string.

If passed an optional +locale+ parameter, the word will be pluralized using rules defined for that language. By default, this parameter is set to :en.

pluralize("post") # => "posts" pluralize("octopus") # => "octopi" pluralize("sheep") # => "sheep" pluralize("words") # => "words" pluralize("CamelOctopus") # => "CamelOctopi" pluralize("ley", :es) # => "leyes"

The reverse of #pluralize, returns the singular form of a word in a string.

If passed an optional +locale+ parameter, the word will be singularized using rules defined for that language. By default, this parameter is set to :en.

singularize("posts") # => "post" singularize("octopi") # => "octopus" singularize("sheep") # => "sheep" singularize("word") # => "word" singularize("CamelOctopi") # => "CamelOctopus" singularize("leyes", :es) # => "ley"

Creates the name of a table like Rails does for models to table names. This method uses the #pluralize method on the last word in the string.

tableize("RawScaledScorer") # => "raw_scaled_scorers" tableize("ham_and_egg") # => "ham_and_eggs" tableize("fancyCategory") # => "fancy_categories"

Capitalizes all the words and replaces some characters in the string to create a nicer looking title. +titleize+ is meant for creating pretty output. It is not used in the Rails internals.

+titleize+ is also aliased as +titlecase+.

titleize("man from the boondocks") # => "Man From The Boondocks" titleize("x-men: the last stand") # => "X Men: The Last Stand" titleize("TheManWithoutAPast") # => "The Man Without A Past" titleize("raiders_of_the_lost_ark") # => "Raiders Of The Lost Ark"

Makes an underscored, lowercase form from the expression in the string.

Changes "::" to "/" to convert namespaces to paths.

underscore("ActiveModel") # => "active_model" underscore("ActiveModel::Errors") # => "active_model/errors"

As a rule of thumb you can think of +underscore+ as the inverse of #camelize, though there are cases where that does not hold:

camelize(underscore("SSLError")) # => "SslError"

Converts just the first character to uppercase.

upcase_first("what a Lovely Day") # => "What a Lovely Day" upcase_first("w") # => "W" upcase_first("") # => ""