Ruby - keys of one hash into values of another hash

问题

I have to hashes like so:

hash1 = {
   "a" => 1,
   "b" => 1,
   "c" => 1,
   "d" => 1
}

hash2 = {
  "1" => 1,
  "2" => 1,
  "3" => 1,
  "4" => 1
}

And I need to merge them so I end up with this:

hash1 = {
  "a" => "1",
  "b" => "2",
  "c" => "3",
  "d" => "4"
}

But I don't know where to begin. Help appreciated.

回答1:

You can try the following:

Hash[hash1.keys.zip(hash2.keys)]

At first, you get array of keys for each hash with hash1.keys and hash2.keys:

["a", "b", "c", "d"]
["1", "2", "3", "4"]

Secondly, you create an array of arrays with hash1.keys.zip(hash2.keys):

[["a", "1"], ["b", "2"], ["c", "3"], ["d", "4"]]

Then with Hash[<...>] you create a Hash where the first value from the first inner array goes as key and the second as value:

{"a"=>"1", "b"=>"2", "c"=>"3", "d"=>"4"}

Example

来源：https://stackoverflow.com/questions/28511878/ruby-keys-of-one-hash-into-values-of-another-hash