utf 8 - Ruby to_json issue with error "illegal/malformed utf-8"

Question

I got an error JSON::GeneratorError: source sequence is illegal/malformed utf-8 when trying to convert a hash into json string. I am wondering if this has anything to do with encoding, and how can I make to_json just treat xAE as it is?

$ irb
2.0.0-p247 :001 > require 'json'
=> true
2.0.0-p247 :002 > a = {"description"=> "iPhonexAE"}
=> {"description"=>"iPhonexAE"}
2.0.0-p247 :003 > a.to_json
JSON::GeneratorError: source sequence is illegal/malformed utf-8
  from (irb):3:in `to_json'
  from (irb):3
  from /Users/cchen21/.rvm/rubies/ruby-2.0.0-p247/bin/irb:16:in `<main>'

Answer 1

xAE is not a valid character in UTF-8, you have to use u00AE instead:

"iPhoneu00AE"
#=> "iPhone?"

Or convert it accordingly:

"iPhonexAE".force_encoding("ISO-8859-1").encode("UTF-8")
#=> "iPhone?"