What does map(&:name) do in this Ruby code?

Question

Trying to understand Ruby a bit better, I ran into this code surfing the Internet:

require \'rubygems\'
require \'activeresource\'



ActiveResource::Base.lo         


        

Answer 1

events.map(&:name)

is exactly equivalent to

events.map{|x| x.name}

it is just convenient syntactic sugar.

For more details, check out the Symbol#to_proc method here. Here, :name is being coerced to a proc.

By the way, this comes up often here - it's just very hard to google or otherwise search for 'the colon thing with an ampersand' :).