Question

I have a string which looks like a hash:

"{ :key_a => { :key_1a => 'value_1a', :key_2a => 'value_2a' }, :key_b => { :key_1b => 'value_1b' } }"

How do I get a Hash out of it? like:

{ :key_a => { :key_1a => 'value_1a', :key_2a => 'value_2a' }, :key_b => { :key_1b => 'value_1b' } }

The string can have any depth of nesting. It has all the properties how a valid Hash is typed in Ruby.

Answer 1

The string created by calling Hash#inspect can be turned back into a hash by calling eval on it. However, this requires the same to be true of all of the objects in the hash.

If I start with the hash {:a => Object.new}, then its string representation is "{:a=>#<Object:0x7f66b65cf4d0>}", and I can’t use eval to turn it back into a hash because #<Object:0x7f66b65cf4d0> isn’t valid Ruby syntax.

However, if all that’s in the hash is strings, symbols, numbers, and arrays, it should work, because those have string representations that are valid Ruby syntax.