require 'json'
JavaScript Object Notation (JSON)
JSON is a lightweight data-interchange format. It is easy for us humans to read and write. Plus, equally simple for machines to generate or parse. JSON is completely language agnostic, making it the ideal interchange format.
Built on two universally available structures: 1. A collection of name/value pairs. Often referred to as an object, hash table, record, struct, keyed list, or associative array. 2. An ordered list of values. More commonly called an array, vector, sequence or list.
To read more about JSON visit: http://json.org
Parsing JSON
To parse a JSON string received by another application or generated within your existing application:
require 'json'
my_hash = JSON.parse('{"hello": "goodbye"}')
puts my_hash["hello"] => "goodbye"
Notice the extra quotes ''
around the hash notation. Ruby expects the argument to be a string and can’t convert objects like a hash or array.
Ruby converts your string into a hash
Generating JSON
Creating a JSON string for communication or serialization is just as simple.
require 'json'
my_hash = {:hello => "goodbye"}
puts JSON.generate(my_hash) => "{\"hello\":\"goodbye\"}"
Or an alternative way:
require 'json'
puts {:hello => "goodbye"}.to_json => "{\"hello\":\"goodbye\"}"
JSON.generate
only allows objects or arrays to be converted to JSON syntax. to_json
, however, accepts many Ruby classes even though it acts only as a method for serialization:
require 'json'
1.to_json => "1"