Question

我一直在尝试在Ruby中组合两个哈希。例如：

h1 = { "a" => 10, "b" => 20, "c"=>34, "d"=>3}
h2 = { "a" => 11, "b" => 21, "d"=>15}

我想要的输出是：

h{"a"=> 10, 11, "b"=>20,21, "c"=> 34, "d"=>3,15}

每个哈希都有相同的密钥，除了第二个哈希可能缺少一些。我想这两个值然后用相同的键表示。

这是我不成功的代码：

h1 = { "a" => 10, "b" => 20, "c"=>34, "d"=>3}   
h2 = {  "a" => 11, "b" => 21, "d"=>15}  
h3= h1.update(h2){|key1, key2, val1, val2 |key1,h2_val=h2}

它给出了：

{"a"=>{"a"=>11, "b"=>21, "d"=>15}, "b"=>{"a"=>11, "b"=>21, "d"=>15}, "c"=>34, "d"=>{"a"=>11, "b"=>21, "d"=>15}}

我刚认识Ruby，所以我想我在这里缺少一些非常基本的东西。我将不胜感激任何帮助。

Answer 1

怎么样：

h1 = { "a" => 10, "b" => 20, "c"=>34, "d"=>3} 
h2 = { "a" => 11, "b" => 21, "d"=>15}

p h1.merge(h2){|key, old, new| Array(old).push(new) } #=> {"a"=>[10, 11], "b"=>[20, 21], "c"=>34, "d"=>[3, 15]}

这就是我如何编写它来组合2个以上的哈希：

h1 = { "a" => 10, "b" => 20, "c"=>34, "d"=>3} 
h2 = { "a" => 11, "b" => 21, "d"=>15}
h3 = { "a" => 11, "b" => 21, "c"=> 1, "d"=>15}

merge_to_array = -> x,y { x.merge(y){|key, old, new| Array(old).push(new)} }

p [h1,h2,h3].reduce &merge_to_array #=> {"a"=>[10, 11, 11], "b"=>[20, 21, 21], "c"=>[34, 1], "d"=>[3, 15, 15]}

Answer 2

h1 = { "a" => 10, "b" => 20, "c"=>34, "d"=>3}
 h2 = { "a" => 11, "b" => 21, "d"=>15}
 arr= []
 arr << h1 << h2
 data=  arr.map(&:to_a).flatten(1).reduce({}) {|h,(k,v)| (h[k] ||= []) << v; h}

它给出了

{"a"=>[10, 11], "b"=>[20, 21], "c"=>[34], "d"=>[3, 15]}

Answer 3

例如，使用#reduce：

h1 = { "a" => 10, "b" => 20, "c"=>34, "d"=>3}
h2 = { "a" => 11, "b" => 21, "d"=>15}
h2.reduce(h1.dup) {|h,(k,v)| h[k] = (h[k] && [h[k], v] || v); h}
# => {"a"=>[10, 11], "b"=>[20, 21], "c"=>34, "d"=>[3, 15]}

Answer 4

你要找的是什么并不完全清楚，因为你的示例输出是无效的，但这就是我要做的就是合并两个哈希而不踩键：

h1 = { "a" => 10, "b" => 20, "c"=>34, "d"=>3}   
h2 = {  "a" => 11, "b" => 21, "d"=>15}  

new_hash = Hash.new{ |h, k| h[k] = [] }
[*h1, *h2].each { |k, v| new_hash[k] << v }

结果是：

new_hash # => {"a"=>[10, 11], "b"=>[20, 21], "c"=>[34], "d"=>[3, 15]}

将两个哈希与一个公共密钥组合在一起

4 个答案: