h1 = { "a" => 100,"b"=> 11 }
h2 = { "b" => 99, "c" => 23 }

resu = h1.merge h2

resu.each_key do |x| 
    resu[x] = []
    resu[x] << (h1[x] || 0)
    resu[x] << (h2[x] || 0)
end

p resu

回复#1 楼 @chenge 略屌。

h1 = { 'a' => 100, 'b' => 11 }
h2 = { 'b' => 99, 'c' => 23 }

res = Hash.new{|h, k| h[k] = [0, 0]}
h1.each{|k, v| res[k][0] = v}
h2.each{|k, v| res[k][1] = v}

p res

回复 3 楼 @reus 更短了！厉害！

Hash[(h1.keys|h2.keys).collect{|k| [k, [h1[k] || 0, h2[k] ||0]]}]

厉害～

#5 楼 @doitian 。。。。。。。目测完胜