How can I merge two hashes without overwritten duplicate keys in Ruby?

Question

Is there an easy or elegant way to merge two hashes without overwriting duplicate keys?

That is, if the key is present in the original hash I don\'t want to

Answer 1

If you have two hashes, options and defaults, and you want to merge defaults into options without overwriting existing keys, what you really want to do is the reverse: merge options into defaults:

options = defaults.merge(options)

Or, if you're using Rails you can do:

options.reverse_merge!(defaults)