hash = { 'foo' => 'bar' }
# Version 1
hash = Hash[hash.map { |k, v| [k.to_sym, v] }]
# Version 2
hash = hash.reduce({}) do |memo, (k, v)|
memo.tap { |m| m[k.to_sym] = v }
end
# Version 3
hash = hash.reduce({}) do |memo, (k, v)|
memo.merge({ k.to_sym => v})
end
# None of the above solutions work with a multi-level hash
# They only work on the first level: {:foo=>"bar", :level1=>{"level2"=>"baz"}}
# The following two variations solve the problem in the same way
multi_hash = { 'foo' => 'bar', 'level1' => { 'level2' => 'baz' } }
# Modify `Object`
class Object
def deep_symbolize_keys
return self.reduce({}) do |memo, (k, v)|
memo.tap { |m| m[k.to_sym] = v.deep_symbolize_keys }
end if self.is_a? Hash
return self.reduce([]) do |memo, v|
memo << v.deep_symbolize_keys; memo
end if self.is_a? Array
self
end
end
multi_hash = multi_hash.deep_symbolize_keys
# Standalone method
def symbolize(obj)
return obj.reduce({}) do |memo, (k, v)|
memo.tap { |m| m[k.to_sym] = symbolize(v) }
end if obj.is_a? Hash
return obj.reduce([]) do |memo, v|
memo << symbolize(v); memo
end if obj.is_a? Array
obj
end
multi_hash = symbolize(multi_hash)