How to change Hash values?

ruby syntax hash

my_hash.each { |k, v| my_hash[k] = v.upcase }

or, if you'd prefer to do it non-destructively, and return a new hash instead of modifying my_hash:

a_new_hash = my_hash.inject({}) { |h, (k, v)| h[k] = v.upcase; h }

This last version has the added benefit that you could transform the keys too.

ruby syntax hash

Since ruby 2.4.0 you can use native Hash#transform_values method:

hash = {"a" => "b", "c" => "d"}new_hash = hash.transform_values(&:upcase)# => {"a" => "B", "c" => "D"}

There is also destructive Hash#transform_values! version.

ruby syntax hash

You can collect the values, and convert it from Array to Hash again.

Like this:

config = Hash[ config.collect {|k,v| [k, v.upcase] } ]

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