JSON object for just an integer - ruby

Question

Silly question, but I'm unable to figure out..
I tried the following in Ruby:
irb(main):020:0> JSON.load('[1,2,3]').class
=> Array
This seems to work. While neither
JSON.load('1').class
nor this
JSON.load('{1}').class
works. Any ideas?

Answer 1

I'd ask the guys who programmed the library. AFAIK, 1 isn't a valid JSON object, and neither is {1} but 1 is what the library itself generates for the fixnum 1.
You'd need to do: {"number" : 1} to be valid json. The bug is that
a != JSON.parse(JSON.generate(a))

Answer 2

I'd say it's a bug:
>> JSON.parse(1.to_json)
JSON::ParserError: A JSON text must at least contain two octets!
from /opt/local/lib/ruby/gems/1.8/gems/json-1.1.3/lib/json/common.rb:122:in `initialize'
from /opt/local/lib/ruby/gems/1.8/gems/json-1.1.3/lib/json/common.rb:122:in `new'
from /opt/local/lib/ruby/gems/1.8/gems/json-1.1.3/lib/json/common.rb:122:in `parse'
from (irb):7
I assume you're using this: (http://json.rubyforge.org/)

Answer 3

JSON only supporting objects is simply not true -- json.org also does not suggest this imo. it was derived from javascript and thus especially strings and numbers are also valid JSON:
var json_string = "1";
var p = eval('(' + json_string + ')');
console.log(p);
// => 1
typeof p
// => "number"
ActiveSupport::JSON properly understands raw value JSON:
require 'active_support/json'
p = ActiveSupport::JSON.decode '1'
# => 1
p.class
# => Fixnum
and so does MultiJson:
require 'multi_json'
p = MultiJson.load '1'
# => 1
p.class
# => Fixnum
so, as a2800276 mentioned, this must be a bug.
but as of this writing, ruby 2's JSON has quirks_mode enabled by default when using the load method.
require 'json'
p = JSON.load '1'
# => 1
p.class
# => Fixnum

Answer 4

The first example is valid. The second two are not valid JSON data. go to json.org for details.

Answer 5

As said only arrays and objects are allowed at the top level of JSON.
Maybe wrapping your values in an array will solve your problem.
def set( value ); #data = [value].to_json; end
def get; JSON.parse( #data )[0]; end

Answer 6

From the very basics of what JSON is:
Data types in JSON can be:
Number
String
Json Object ... (and some more)
Reference to see complete list of Json data types
Now any Json data has to be encapsulated in 'Json Object' at the top level.
To understand why is this so, you can see that without a Json Object at the top level, everything would be loose and you could only have only one of the data type in the whole of Json. i.e. Either a number, a string, a array, a null value etc... but only one.
'Json Object' type has a fixed format of 'key' : 'value' pair.
You cannot store just the value. Thus you cannot have something like {1}.
You need to put in the correct format, i.e. 'key' : 'value' pair.