what is the purpose of using square brackets in json? [duplicate]

Question

I am new to json. Some json examples i have seen have data within the curly braces and some json examples have subdata within square brackets.

{ "glossary": {     "title": "example glossary",     "GlossDiv": {         "title": "S",         "GlossList": {             "GlossEntry": {                 "ID": "SGML",                 "SortAs": "SGML",                 "GlossTerm": "Standard Generalized Markup Language",                 "Acronym": "SGML",                 "Abbrev": "ISO 8879:1986",                 "GlossDef": {                     "para": "A meta-markup language, used to create markup languages such as DocBook.",                     "GlossSeeAlso": ["GML", "XML"]                 },                 "GlossSee": "markup"             }         }     } } } 

From http://json.org/example.html

What is the need/purpose of having data within the square brackets?

regards

Answer 1

The square brackets produce a list/array.

The curly brackets produce an object with key/value pairs.

The list can then be a value of a key/value pair.

Answer 2

[] means an array of object (a list) and {} means it will be an object.

Example:

{     "ID":"test",     "sports": [         "volley-ball",         "badminton"     ] } 

To get the ID, you can do: myjsonobject.ID (here you will get "test")

And for sports: myjsonobject.sports[0] (here you will get "volley-ball")