如何优雅地为'嵌套'哈希symbolics_keys [英] How to elegantly symbolize_keys for a 'nested' hash
问题描述
hash1 = {one=> 1,two=> 2,三=> 3}
hash2 = hash1.reduce({}){| h,(k,v)| h.merge(k => hash1)}
hash3 = hash2.reduce({}){| h,(k,v)| h.merge(k => hash2)}
hash4 = hash3.reduce({}){| h,(k,v)| h.merge(k => hash3)}
hash4是一个'嵌套'使用字符串键和类似的'嵌套'散列值。
Hash in Rails中的'symbolize_keys'方法让我们可以轻松地将字符串键转换为符号。但是我正在寻找一种优雅的方法来将所有键(主键和散列表中的所有散列的键)转换为符号。
点是从我的( imo )丑陋的解决方案中拯救我自己:
class Hash
def symbolize_keys_and_hash_values
symbolize_keys.reduce({})do | h,(k,v)|
new_val = v.is_a?(哈希)? v.symbolize_keys_and_hash_values:v
h.merge({k => new_val})
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hash4.symbolize_keys_and_hash_values#=> ;所需结果
仅供参考:安装程序是Rails 3.2.17和Ruby 2.1.1
更新:
对于Rails< = 5.0,回答为 hash4.deep_symbolize_keys
对于Rails> 5
,答案是 JSON.parse(JSON [hash4],symbolize_names:true)
> 有一个 deep_symbolize_keys
Rails中的方法
hash4.deep_symbolize_keys !
Consider the following code:
hash1 = {"one" => 1, "two" => 2, "three" => 3}
hash2 = hash1.reduce({}){ |h, (k,v)| h.merge(k => hash1) }
hash3 = hash2.reduce({}){ |h, (k,v)| h.merge(k => hash2) }
hash4 = hash3.reduce({}){ |h, (k,v)| h.merge(k => hash3) }
hash4 is a 'nested' hash i.e. a hash with string keys and similarly 'nested' hash values.
The 'symbolize_keys' method for Hash in Rails lets us easily convert the string keys to symbols. But I'm looking for an elegant way to convert all keys (primary keys plus keys of all hashes within hash4) to symbols.
The point is to save myself from my (imo) ugly solution:
class Hash
def symbolize_keys_and_hash_values
symbolize_keys.reduce({}) do |h, (k,v)|
new_val = v.is_a?(Hash) ? v.symbolize_keys_and_hash_values : v
h.merge({k => new_val})
end
end
end
hash4.symbolize_keys_and_hash_values #=> desired result
FYI: Setup is Rails 3.2.17 and Ruby 2.1.1
Update:
Answer is hash4.deep_symbolize_keys
for Rails <= 5.0
Answer is JSON.parse(JSON[hash4], symbolize_names: true)
for Rails > 5
There's a deep_symbolize_keys
method in Rails
hash4.deep_symbolize_keys!
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