ClassName to class_name

Question

Hi,

I'm sure this is an easy one for you geeks:

Say I have a String "ThisIsMyString" and I want to format it like "this_is_my_string" using Ruby.

How do I do that?

Matt

Answer 1

class String def to_under_score (gsub(/[A-Z]) { |p| "_" + p.downcase })[1..-1] end end

"MyTestCase".to_under_score => "my_test_case"

From http://www.ruby-forum.com/topic/113697#265696

Answer 2

Ruby Facets has a function to do this: String#underscore. Here's the source of it:

  def underscore
    gsub(/::/, '/').
    gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2').
    gsub(/([a-z\d])([A-Z])/,'\1_\2').
    tr("-", "_").
    downcase
  end

Answer 3

If you have access to ActiveSupport from the Rails project, it's as simple as

require 'activesupport'
"ThisIsMyString".underscore

Answer 4

If you have access to ActiveSupport (as in Rails, but usable externally) you can use the underscore method in the Inflector module.

"ClassName".underscore # => class_name