JSON

JSON (JavaScript Object Notation) is a way of expressing information.^[1] JSON is usually easy to understand. It can express information like XML.^[2] It is based on JavaScript's notation for object literals.^[3] However, JSON is stricter.^[3]

JSON and XML are both often used in AJAX.^[4] Even though JSON is named after JavaScript, it can be used in other programming languages, such as Python (PHP, etc.)^[5]

Example

This is an example of JSON:

{
     "firstName": "John",
     "lastName" : "Smith",
     "age"      : 25,
     "address"  :
     {
         "streetAddress": "21 2nd Street",
         "city"         : "New York",
         "state"        : "NY",
         "postalCode"   : "10021"
     },
     "phoneNumber":
     [
         {
           "type"  : "",
           "number": "212 555-1234"
         },
         {
           "type"  : "fax",
           "number": "646 555-4567"
         }
     ]
 }

JSON Encoding and Decoding in Python

Encoding:

import json

sampleDict = {
  "firstName": "John",
  "lastName" : "Smith"
}

sampleJson = json.dumps(sampleDict, indent=4)

Decoding:

import json

# A JSON string or can be a JSON response
sampleJson = """{ "firstName": "John", "lastName" : "Smith"}"""

sampleDict = json.loads(sampleJson)
print(sampleDict['firstName'])
print(sampleDict['lastName'])