method

underscore

v3.2.13 - Show latest stable - Class: ActiveSupport::Inflector

underscore(camel_cased_word)

public

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

Changes ‘::’ to ‘/’ to convert namespaces to paths.

Examples:

"ActiveModel".underscore         # => "active_model"
"ActiveModel::Errors".underscore # => "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:

"SSLError".underscore.camelize # => "SslError"

# File activesupport/lib/active_support/inflector/methods.rb, line 77
    def underscore(camel_cased_word)
      word = camel_cased_word.to_s.dup
      word.gsub!(/::/, '/')
      word.gsub!(/(?:([A-Za-z\d])|^)(#{inflections.acronym_regex})(?=\b|[^a-z])/) { "#{$1}#{$1 && '_'}#{$2.downcase}" }
      word.gsub!(/([A-Z\d]+)([A-Z][a-z])/,'\1_\2')
      word.gsub!(/([a-z\d])([A-Z])/,'\1_\2')
      word.tr!("-", "_")
      word.downcase!
      word
    end

underscore

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