Comments on: Picking values from Ruby hashes

By: John Long

John Long — Fri, 27 Jun 2008 03:47:13 +0000

How about:

class Hash def pick(*values) pairs = select { |k,v| values.include?(k) } Hash[*pairs.flatten] end end

hash.pick(:foo, :bar) #returns {:bar=>"baz", :foo=>"bar"}

By: neerajdotname

neerajdotname — Thu, 26 Jun 2008 20:51:54 +0000

You can use facets Hash method slice.

h.slice(:foo,:bar) #=> another hash

h.slice(:foo,:bar).to_a #=> to convert the hash into array.

http://facets.rubyforge.org/doc/index.html

By: Scott Moonen

Scott Moonen — Thu, 26 Jun 2008 19:59:35 +0000

If you’re using Rails, then ActiveSupport::CoreExtensions::Hash::Slice provides a slice() method to slice a hash, and this is automatically added to the Hash class for you. Its usage is exactly as given above, except that it returns a hash instead of an array of pairs.