leejarvis · January 25, 2012 12:32
diff --git a/gistfile1.rb b/gistfile1.rb
 #!/usr/bin/env ruby

 # dont try this at home

 items = [{ a: 1, b: 2 }, { a: 1, b: 3 }, { a: 4, b: 5 }]
 items = items.each_with_object(Hash.new { |h, k| h[k] = [] }) { |i, o| o[i[:a]] << i[:b] }.map { |k, v| [k, v.join(', ')] }

 p items #=> [[1, "2, 3"], [4, "5"]]
	#!/usr/bin/env ruby

	# dont try this at home

	items = [{ a: 1, b: 2 }, { a: 1, b: 3 }, { a: 4, b: 5 }]
	items = items.each_with_object(Hash.new { \|h, k\| h[k] = [] }) { \|i, o\| o[i[:a]] << i[:b] }.map { \|k, v\| [k, v.join(', ')] }

	p items #=> [[1, "2, 3"], [4, "5"]]