ruby-on-rails - Ruby .map 哈希值到数组中的键值对
问题描述
a = {one: 2, two: 3}.map{|k,v| {k => v}} # => [{:one=>2}, {:two=>3}]
a[0] # => {:one=>2}
a[0].class # => Hash
a[0].key # ~> ArgumentError: wrong number of arguments (given 0, expected 1)
预期输出:
[{one: 2}, {two: 3}]
这将导致 a[0].key >> :one
为什么我无法获取数组中第一项的键值?
解决方案:keys.first。