データ yaml json

yaml

• 構造化したデータを表現するモノ

記事

基本

require 'yaml'

yaml_data = <<-DATA
- RED
- GREEN
- BLU

DATA

YAML.load(yaml_data)

# リテラル
yaml_data = <<-DATA
- RED
- GREEN
- BLU

DATA

p YAML.load(yaml_data)


# リテラル出力
➜  Desktop ruby sample.rb
["RED", "GREEN", "BLU"]
"\ndefault: &default\n  adapter: mysql2\n  host: 127.0.0.1\n  encoding: utf8\n  pool: 5\n  username: root\n  password:\n  reconnect: false\n\ndevelopment:\n  <<: *default\n  database: development\n\ntest:\n  <<: *default\n  database: test\n\n\n"


#yml形式

database = <<-DATA

default: &default
  adapter: mysql2
  host: 127.0.0.1
  encoding: utf8
  pool: 5
  username: root
  password:
  reconnect: false

development:
  <<: *default
  database: development

test:
  <<: *default
  database: test


DATA

p YAML.load(database)


#yml形式　出力

➜  Desktop ruby sample.rb
["RED", "GREEN", "BLU"]
{"default"=>{"adapter"=>"mysql2", "host"=>"127.0.0.1", "encoding"=>"utf8", "pool"=>5, "username"=>"root", "password"=>nil, "reconnect"=>false}, "development"=>{"adapter"=>"mysql2", "host"=>"127.0.0.1", "encoding"=>"utf8", "pool"=>5, "username"=>"root", "password"=>nil, "reconnect"=>false, "database"=>"development"}, "test"=>{"adapter"=>"mysql2", "host"=>"127.0.0.1", "encoding"=>"utf8", "pool"=>5, "username"=>"root", "password"=>nil, "reconnect"=>false, "database"=>"test"}}

json

• json（JavaScript Object Notation）とは

javascriptのオブジェクト

• 記事
  https://www.sejuku.net/blog/16196#json

require 'json'

yaml_data = <<-DATA
["Red","Blue","Red"]

DATA

JSON.load(yaml_data)

# json は基本はオブジェクト

example.json

{
    "ruby": {
      "rails":30000
    },
    "python": {
      "django":25000
    }
  }

require 'json'

File.open("example.json") do |file|
  hash = JSON.load(file)
  p hash
end


hash = JSON.parse('{"ruby":{"rails":30000},"python":{"django":25000}}')
p hash
{"ruby"=>{"rails"=>30000}, "python"=>{"django"=>25000}}

# 文字列型のjsonもある

- parse

hash = JSON.parse('{"ruby":{"rails":30000},"python":{"django":25000}}')

p hash
{"ruby"=>{"rails"=>30000}, "python"=>{"django"=>25000}}

• json 作成

generate

ハッシュ　→ jsonに

require 'json'
hash = JSON.generate({"ruby":{"rails":30000},"python":{"django":25000}})
p hash

to_json

# ruby で用意してくれている

require 'json'
hash = {"ruby":{"rails":30000},"python":{"django":25000}}.to_json
p hash