ruby - 在 Ruby 中将散列展平为字符串

Question

有没有办法将散列扁平化为字符串，并在键和值之间以及键/值对之间使用可选的分隔符？

例如，print {:a => :b, :c => :d}.flatten('=','&') 应该打印 a=b&c=d

我写了一些代码来做到这一点，但我想知道是否有更简洁的方法:

class Hash
  def flatten(keyvaldelimiter, entrydelimiter)
    string = ""
    self.each do
      |key, value|
      key = "#{entrydelimiter}#{key}" if string != "" #nasty hack
      string += "#{key}#{keyvaldelimiter}#{value}"  
    end
    return string
  end
end

print {:a => :b, :c => :d}.flatten('=','&') #=> 'c=d&a=b'

谢谢

Answer 1

我不会覆盖已经定义的 .flatten:

Returns a new array that is a one-dimensional flattening of this hash. That is, for every key or value that is an array, extract its elements into the new array. Unlike Array#flatten, this method does not flatten recursively by default. If the optional level argument determines the level of recursion to flatten.

这是我所知道的最简单的方法:

{:a => 100, :b => 200}.map{|k,v| "#{k}=#{v}"}.join('&')
# => "a=100&b=200"