1. JavaScript Object Notation
JSON
JavaScript Object Notation

2. JavaScript Object Notation
Plain text file format
Although originally derived from the JavaScript scripting language, JSON is a language-independent data format.
Whitespace (outside of strings) isn't meaningful.
One data type allowed per file (but often it is a container)

3. JSON string
string: a sequence of zero or more Unicode characters. Strings are delimited with double-quotation marks and support a backslash escaping syntax.
"Hi\nEveryone"

4. JSON Strings Which of these are JSON strings? Josh "Josh\n" "\_(^^)_/"
""

5. JSON number
number: a signed decimal number that may contain a fractional part and may use exponential E notation. 4
12.5
6.022e23
-5.6

6. JSON array
array: an ordered list of zero or more values, each of which may be of any type. []
[4, "Josh", true]
[[], null]

7. JSON object
object: an unordered collection of name/value pairs where the names (also called keys) are strings.
{"name":"Josh", "age":17, "section":[1,2]}

8. JSON values (null and boolean)
null: empty value
null
boolean: either of the values
true
false

9. Example JSON File { "name":"josh", "pets": [{ "name": "zoe", "age":7,
"birthday":null,
"species":"dog",
"commands":["fetch", "shake", "come"]
}],
"employed":true }

10. JSON Schema
A schema is a definition of how the data should be formatted.
Schema can be used for validation.
JSON schema is currently in a working draft, but is already very broadly used.
Info available at: schema.org/

11. JSON Schema Questions the schema should answer: What is the data?
Example JSON File {
"id": 1,
"name": "A green door",
"price": 12.50,
"tags": ["home", "green"] }
Questions the schema should answer:
What is the data?
What is id?
Is name required?
Can price be 0?
Are all tags strings?

12. What is the data? Example JSON File { "id": 1, "name": "A green door",
JSON Schema File
{ "title": "Product",
"description": "Product from catalog",
"type": "object" }
What is the data?
Example JSON File {
"id": 1,
"name": "A green door",
"price": 12.50,
"tags": ["home", "green"] }

13. What is id? Example JSON File { "id": 1, "name": "A green door",
JSON Schema File
{ "title": "Product",
"description": "Product from catalog",
"type": "object",
"properties": {
"id": {
"description": "unique id",
"type": "integer" } },
"required": ["id"] }
What is id?
Example JSON File {
"id": 1,
"name": "A green door",
"price": 12.50,
"tags": ["home", "green"] }

14. Is name required? Example JSON File { "id": 1, "name": "A green door",
JSON Schema File
{ "title": "Product",
"description": "Product from catalog",
"type": "object",
"properties": {
"id": {
"description": "unique id",
"type": "integer" },
"name": {
"description": "Name item",
"type": "string" } },
"required": ["id", "name"] }
Is name required?
Example JSON File {
"id": 1,
"name": "A green door",
"price": 12.50,
"tags": ["home", "green"] }

15. Can price be 0? Example JSON File { "id": 1, "name": "A green door",
JSON Schema File
{ "title": "Product",
"description": "Product from catalog",
"type": "object",
"properties": {
"id": {
"description": "unique id",
"type": "integer" },
"name": {
"description": "Name item",
"type": "string" },
"price": {
"type": "number",
"minimum": 0,
"exclusiveMinimum": true } },
"required": ["id", "name", "price"] }
Can price be 0?
Example JSON File {
"id": 1,
"name": "A green door",
"price": 12.50,
"tags": ["home", "green"] }

16. Are all tags strings? Example JSON File { "id": 1,
JSON Schema File
{ "title": "Product",
"description": "Product from catalog",
"type": "object",
"properties": {
"id": {
"description": "unique id",
"type": "integer" },
"name": {
"description": "Name item",
"type": "string" },
"price": {
"type": "number",
"minimum": 0,
"exclusiveMinimum": true },
"tags": {
"type": "array",
"items": {
"minItems": 1,
"uniqueItems": true } },
"required": ["id", "name", "price"] }
Are all tags strings?
Example JSON File {
"id": 1,
"name": "A green door",
"price": 12.50,
"tags": ["home", "green"] }

17. JSON Schema Are JSON Schema required for interpretation of JSON data?
JSON Schema File
{ "title": "Product",
"description": "Product from catalog",
"type": "object",
"properties": {
"id": {
"description": "unique id",
"type": "integer" },
"name": {
"description": "Name item",
"type": "string" },
"price": {
"type": "number",
"minimum": 0,
"exclusiveMinimum": true },
"tags": {
"type": "array",
"items": {
"minItems": 1,
"uniqueItems": true } },
"required": ["id", "name", "price"] }
Are JSON Schema required for interpretation of JSON data?
Yes No