What does map(&:name) mean in Ruby?

Question

I found this code in a RailsCast:

def tag_names
  @tag_names || tags.map(&:name).join(\' \')
end

What does the (&:name)

Answer 1

map(&:name) takes an enumerable object (tags in your case) and runs the name method for each element/tag, outputting each returned value from the method.

It is a shorthand for

array.map { |element| element.name }

which returns the array of element(tag) names