JSON | Data Types

JSON (JavaScript Object Notation) is most widely used data format for data interchange on the web. JSON is a lightweight text based, data-interchange format and it completely language independent. It is based on a subset of the JavaScript programming language and it is easy to understand and generate. 
JSON supports mainly 6 data types: 
 

1. string
2. number
3. boolean
4. null
5. object
6. array

Note: string, number, boolean, null are simple data types or primitives data types whereas object and array are referred as complex data types. 

1. String: JSON strings must be written in double quotes like C-language there are various special characters(Escape Characters) in JSON that you can use in strings such as \ (backslash), / (forward slash), b (backspace), n (new line), r (carriage return), t (horizontal tab) etc. 
   Example: 
    

{ "name":"Vivek" }

{ "city":"Delhi\/India" }

here \/ is used for Escape Character / (forward slash).

1. Number: Represented in base 10 and octal and hexadecimal formats are not used. 
   Example: 
    

{ "age": 20 }
{ "percentage": 82.44}

1. Boolean: This data type can be either true or false. 
   Example: 
    

{ "result" : true }

1. Null: It is just a define nullable value. 
   Example: 
    

{
  "result" : true,
  "grade" : null,
  "rollno" : 210
}

1. Object: It is a set of name or value pairs inserted between {} (curly braces). The keys must be strings and should be unique and multiple key and value pairs are separated by a, (comma). 
   Syntax: 
    

{ key : value, .......}

1. Example: 
    

{
"Geek":{ "name":"Peter", "age":20, "score": 50.05}
}

1. Array: It is an ordered collection of values and begins with [ (left bracket) and ends with ] (right bracket). The values of array are separated by ,(comma). 
   Syntax: 
    

[ value, .......]

1. Example: 
    

{
"geek":[ "Sahil", "Vivek", "Rahul" ]
}

{
  "collection" : [
        {"id" : 101},
        {"id" : 102},
        {"id" : 103}
  ]
}

Example of JSON document: 
 

{
  "Geeks" : [
    { 
      "Geekname" : "Sahil kumar",
      "subject" : "Data structures",
      "Articles" : 10
      },
    { 
      "Geekname" : "Pawan singh",
      "subject" : "Algorithms",
      "Articles" : 16 
      },
    { 
      "Geekname" : "Ayush Goel",
      "subject" : "Networking",
      "Articles" : 7
      }
  ]
}