Parsing a JSON string in Ruby

This looks like JavaScript Object Notation (JSON). You can parse JSON that resides in some variable, e.g. json_string, like so:

require 'json'
JSON.parse(json_string)

If you’re using an older Ruby, you may need to install the json gem.


There are also other implementations of JSON for Ruby that may fit some use-cases better:

  • YAJL C Bindings for Ruby
  • JSON::Stream

As of Ruby v1.9.3 you don't need to install any Gems in order to parse JSON, simply use require 'json':

require 'json'

json = JSON.parse '{"foo":"bar", "ping":"pong"}'
puts json['foo'] # prints "bar"

See JSON at Ruby-Doc.


Just to extend the answers a bit with what to do with the parsed object:

# JSON Parsing example
require "rubygems" # don't need this if you're Ruby v1.9.3 or higher
require "json"

string = '{"desc":{"someKey":"someValue","anotherKey":"value"},"main_item":{"stats":{"a":8,"b":12,"c":10}}}'
parsed = JSON.parse(string) # returns a hash

p parsed["desc"]["someKey"]
p parsed["main_item"]["stats"]["a"]

# Read JSON from a file, iterate over objects
file = open("shops.json")
json = file.read

parsed = JSON.parse(json)

parsed["shop"].each do |shop|
  p shop["id"]
end

It looks like a JSON string. You can use one of many JSON libraries and it's as simple as doing:

JSON.parse(string)

Tags:

Ruby

Json