How do I sort an array of hashes by a value in the hash?

Ruby’s sort doesn’t sort in-place. (Do you have a Python background, perhaps?)

Ruby has sort! for in-place sorting, but there’s no in-place variant for sort_by in Ruby 1.8. In practice, you can do:

sorted = sort_me.sort_by { |k| k["value"] }
puts sorted

As of Ruby 1.9+, .sort_by! is available for in-place sorting:

sort_me.sort_by! { |k| k["value"]}