json.org example string: {"nickname":null,"num":100,"balance":1000.21,"is_vip":true,"name":"foo"}

require 'yaml'

>> x = YAML::load %{{"nickname": null, "num": 100, "balance": 1000.21, "is_vip": true, "name": "foo"}}
=> {"name"=>"foo", "nickname"=>nil, "num"=>100, "is_vip"=>true, "balance"=>1000.21}
>> x["name"]
=> "foo"
>> x.each_key{|x| p x}
"name"
"nickname"
"num"
"is_vip"
"balance"