JSON Concepts

Internal

• JSON

Data Types

JSON data types are: null, Booleans, Strings, Numbers, Objects (which can be thought of as Maps) and Arrays.

Booleans

Booleans are represented as

true
false

and they are not quoted.

Strings

Strings are represented as:

"this is a string"

and they are quoted. Always use double quotes ("), never use single quotes (').

Numbers

Numbers are represented as:

10

and they are not quoted.

Objects

Objects are enclosed in curly brackets "{}" and contain key/value pairs. The key and the value are separated by colon (":"). The pairs are delimited by commas (","):

{
  "id" : 42,
  "name" : "John Doe",
  "married" : true
  "kids" : [ "Alice", "Bob" ]
}

Arrays

Array elements are enclosed in brackets "[", and they are separated by commas:

[ "one element", "another element" ]

Comments

JSON does not support comments: https://plus.google.com/+DouglasCrockfordEsq/posts/RK8qyGVaGSr

A comment can be simulated as follows:

{
   "comment":"this is a comment",

   ...

} 

Single Quotes vs. Double Quotes

Never use single quotes ('), always use double quotes (").

JSON Schema

JSON Schema is a vocabulary that allows to annotate and validate JSON documents. The schema describes the data format, and provides complete structural validation. Example:

{
  "description":"A customer",
  "type":"object",
  "properties":
   {
      "first": {"type": "string"},
      "last" : {"type" : "string"}
   }
}

More http://json-schema.org.