Best way to convert strings to symbols in hash

Question

What's the (fastest/cleanest/straightforward) way to convert all keys in a hash from strings to symbols in Ruby?

This would be handy when parsing YAML.

my_hash = YAML.load_file('yml') 

I'd like to be able to use:

my_hash[:key]  

Rather than:

my_hash['key'] 

Answer 1

Here's a better method, if you're using Rails:

params.symbolize_keys

The end.

If you're not, just rip off their code (it's also in the link):

myhash.keys.each do |key|   myhash[(key.to_sym rescue key) || key] = myhash.delete(key) end 

Answer 2

In Ruby >= 2.5 (docs) you can use:

my_hash.transform_keys(&:to_sym) 

Using older Ruby version? Here is a one-liner that will copy the hash into a new one with the keys symbolized:

my_hash = my_hash.inject({}){|memo,(k,v)| memo[k.to_sym] = v; memo} 

With Rails you can use:

my_hash.symbolize_keys my_hash.deep_symbolize_keys