Ruby-on-rails 如何将哈希键从“符号”更改为“字符串”？
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How to change hash keys from `Symbol`s to `String`s?
提问by user12882
I am using Ruby on Rails 3.2.2 and I would like to "easily" / "quickly" change hash keys from Symbols to Strings. That is, from {:one => "Value 1", :two => "Value 2", ...}to {"one" => "Value 1", "two" => "Value 2", ...}.
我正在使用 Ruby on Rails 3.2.2，我想“轻松”/“快速”将哈希键从Symbols更改为Strings。也就是说，从{:one => "Value 1", :two => "Value 2", ...}到{"one" => "Value 1", "two" => "Value 2", ...}。
How can I make that by using less code as possible?
我怎样才能通过尽可能少的代码来做到这一点？
回答by Viktor Trón
simply call stringify_keys(or stringify_keys!)
只需调用stringify_keys（或stringify_keys!）
回答by jdoe
Use stringify_keys/stringify_keys!methods of the Hashclass.
使用stringify_keys/类的stringify_keys!方法Hash。
You can also use some_hash.with_indifferent_accessto return a Hash instance where your key can be specified as symbols or as strings with no difference.
您还可以使用some_hash.with_indifferent_access返回一个 Hash 实例，其中您的键可以指定为符号或字符串，没有区别。
回答by eli
stringify_keysis nice, but only available in Rails.
Here's how I would do it in a single line, with zero dependencies:
stringify_keys很好，但仅在 Rails 中可用。下面是我将如何在一行中完成它，零依赖：
new_hash = Hash[your_hash.collect{|k,v| [k.to_s, v]}]
This works on Ruby 1.8.7 and up. If you are working with Ruby 2.1, you can do:
这适用于 Ruby 1.8.7 及更高版本。如果您使用 Ruby 2.1，您可以执行以下操作：
new_hash = a.collect{|k,v| [k.to_s, v]}.to_h
Note that this solution is not recursive, nor will it handle "duplicate" keys properly. eg. if you have :keyand also "key"as keys in your hash, the last one will take precedence and overwrite the first one.
请注意，此解决方案不是递归的，也不会正确处理“重复”键。例如。如果您有:key和 也"key"作为哈希中的键，则最后一个将优先并覆盖第一个。
回答by Ery
stringify_keys from rails
来自 rails 的 stringify_keys
http://api.rubyonrails.org/classes/Hash.html#method-i-stringify_keys
http://api.rubyonrails.org/classes/Hash.html#method-i-stringify_keys
hash = { name: 'Rob', age: '28' }
hash.stringify_keys
# => { "name" => "Rob", "age" => "28" }
回答by rik.vanmechelen
there is a nice library that does the trick, the library is "facets/hash/rekey" and the method is rekey!. Se my example below of how to use it. It is just a copy past of
有一个很好的库可以解决这个问题，库是“facets/hash/rekey”，方法是rekey！。下面是我如何使用它的示例。这只是一个复制过去
> require 'facets/hash/rekey'
=> true
> a = {:one => "Value 1", :two => "Value 2"}
=> {:one=>"Value 1", :two=>"Value 2"}
> a.rekey!(&:to_s)
=> {"one"=>"Value 1", "two"=>"Value 2"}
> a
=> {"one"=>"Value 1", "two"=>"Value 2"}
回答by abhas
new_hash = Hash.new
your_hash.each{ |k,v| new_hash[k.to_s] = v }
new_hash will be same as your_hash but with string keys
new_hash 将与 your_hash 相同，但带有字符串键
回答by pguardiario
I came here to see if there was something better than:
我来这里是为了看看是否有比以下更好的东西：
JSON.parse(hash.to_json)
But I think I'll stick with what I have.
但我想我会坚持我所拥有的。
回答by kjian
You can transfer the key from symbols to strings explicitly:hash = hash.map { |k, v| [k.to_s, v] }.to_h
您可以显式地将键从符号转移到字符串：hash = hash.map { |k, v| [k.to_s, v] }.to_h
回答by mooreds
hash = hash.transform_keys(&:to_s)turns all keys from symbols into strings.
hash = hash.transform_keys(&:to_s)将所有键从符号转换为字符串。
More here: https://ruby-doc.org/core-2.6.3/Hash.html#method-i-transform_keys
更多信息：https: //ruby-doc.org/core-2.6.3/Hash.html#method-i-transform_keys
This was added in ruby 2.5: https://bugs.ruby-lang.org/issues/13583
这是在 ruby 2.5 中添加的：https: //bugs.ruby-lang.org/issues/13583
