JSON in a Nutshell

JSON consists of key-value pairs in the form of "key": value. The key-part is always surrounded by ". The value-part can be one of four types:

Numbes

Numbers are written as 123, 1, 1.0, 0.545, .545.

Text

Text (strings) are written inside ": "some text here".

Arrays

An array is a list of objects, written inside [ and ], separated by commas: [1,2,3], ["hello","my","friend!"].

Objects

An object (hence the name object notation) is another set of key-value pairs, written inside { and }, separated by commas:

{
  "name": "Bert", 
  "age": 28, 
  "hobbies":[
    "reading", 
    "drawing", 
    "walking"
  ], 
  "lives in": {
     "name": "Edinburgh", 
     "country": "UK"
  }
}

As you see, objects can contain objects, which in turn can contain other objects and so on. Note that intendation is not important but greatly improves readability.