Ruby将特定的哈希键映射到新密钥

Question

I've got an array full of hashes of which I want to combine specific keys to a new one, eg

[{ firstname: 'john', lastname: 'doe', something: 'else', key: ... }, { firstname: 'Joe', lastname: 'something', something: 'bla', key:... }]

should become

[{ name: 'john doe' },{ name: 'Joe something' }]

Please note: there are more keys in the hash as first and lastname. Is there a common ruby method to do this? Thanks!

Answer 1

Just do as

array = [{ firstname: 'john', lastname: 'doe' }, { firstname: 'Joe', lastname: 'something' }]
array.map { |h| { :name => h.values_at(:firstname, :lastname) * " " } }
# => [{:name=>"john doe"}, {:name=>"Joe something"}] 

Read this Hash#values_at and Array#* .

Answer 2

This is:

a = [{ firstname: 'john', lastname: 'doe' }, { firstname: 'Joe', lastname: 'something' }]
a.map { |n| { name: n.values.join(' ') } }
# => [{:name=>"john doe"}, {:name=>"Joe something"}]