What are the Different Datatypes in JSON

JSON supports the following 6 data types, the first 4 are primitive data types and the other 2 are complex types.

Let’s see some more details on each of them.

string

• It is a sequence of Unicode characters in double quotes. Its length can be 0 or more
• Special characters are escaped with a backslash

Following are various special characters with backslash escaping.

Example

{
    "name": "John Davis",
    "address": "977 Crescent St.\nOld Bridge, NJ 08857",
    "forward": "Symbol for forward slash is /",
    "first_letter": "a",
    "error_msg": ""
}

number

• A number can have an integer or floating-point value.
• Both positive and negative values are supported.
• e-notation is supported by having a value, integer or floating point, followed by e or E, then by the power of 10 to multiply by. For example, pi is 3.147e8

Example

{
    "num1": 60,
    "num2": -35,
    "num3": 0.5,
    "num4": -133.234,
    "pi": 314700000
}

boolean

• boolean values are simply true or false.
• booleans are not enclosed in quotes.

Example

{
    "participated": true,
    "cleared": false
}

null

• null means empty. When a value is not found then it is represented as null.
• null is special in JSON, it shows that the value is not there.
• null does not need to be enclosed in quotes.

Example

{
    "max_score": 70,
    "avg_score": null
}

array

• an array is used to store an ordered collection of values.
• an array can have 0 or more values.
• array values can be of different data types.
• array values are comma-separated and enclosed in square brackets i.e. []
• an array can also contain objects.

Example

{
  "names": ["John", "Michael", "Lewis", "Jordan"],
  "ids": [101, 102, 203, 404],
  "random": ["John", 45, null, false, 3.4],
  "allowed_cards": []
}

Objects in an array

{
  "candidates": [
    {
      "first_name": "John",
      "cleared": true
    },
    {
      "first_name": "Jordan",
      "cleared": false
    },
    {
      "first_name": "Davis",
      "cleared": true
    }
  ]
}

object

• an object is an unordered collection of key/value pairs.
• objects are separated by commas and enclosed in curly braces.
• An object can have 0 or more values.
• The values in an object are allowed to have different data types.
• an object can contain an array.

Example

{
    "first_name": "John",
    "cleared": true,
    "age": 45,
    "address": {
        "flat_no": 977,
        "street": "Crescent St.",
        "state": "NJ"
    },
    "allowed_cards": [
        "American Express",
        "Visa"
    ]
}