What is JSON?

JSON (JavaScript Object Notation) is a lightweight data-interchange text format that is so easy for humans to read and write, and also works easily for machines to parse and generate.

Why JSON?

When we have a question, why JSON is used, it’s widely used to transmit data between a server and a web application, or between different parts of a software system.

How JSON Syntax Works

JSON (JavaScript Object Notation) follows a strict and simple syntax designed to be both human-readable and machine-parseable. Here’s a breakdown of how its syntax works:

Basic JSON Structure

JSON is built on two structures:

Objects (unordered key/value pairs)

				
					Syntax:
{
  "key": "value"
}

Arrays (ordered lists of values)

				
					Syntax:
[
  "value1",
  "value2"
]

JSON Syntax Rules

Rule DescriptionExample
Data is in name/value pairs"name": "John"
Data is separated by commas"age": 25, "city": "NY"
Curly braces hold objects{ "name": "John", "age": 25 }
Square brackets hold arrays"colors": ["red", "green", "blue"]
Keys must be stringsMust be in double quotes: "name"
Values can bestring, number, object, array, boolean, or null

Example JSON

				
					{
  "name": "Alice",
  "age": 30,
  "isStudent": false,
  "skills": ["Python", "JavaScript"],
  "address": {
    "city": "New York",
    "zip": "10001"
  },
  "middleName": null
}

Types of JSON Data

In JSON, data is represented using a limited set of data types that are simple and widely supported across programming languages. Here are the six core data types in JSON:

1. String
A sequence of characters enclosed in double quotes (“)
Must use double quotes (not single).

Example:

				
					"name": "Alice",

2. Number
Can be an integer or a floating-point number.
No quotes around numbers.

Example:

				
					"age": 25,
"height": 5.8

3. Boolean
Represents a logical value: true or false.

Example:

				
					"isStudent": false

4. Array
An ordered list of values (can be of mixed types).
Enclosed in square brackets [].

Example:

				
					"skills": ["Python", "JavaScript", "C++"]

5. Object
A collection of key-value pairs.
Enclosed in curly braces {}.
Keys must be strings; values can be any valid JSON type.

Example:

				
					"address": {
    "city": "New York",
    "zip": "10001"
}

6. null
Represents an empty or non-existent value.

Example:

				
					"middleName": null

These types can be nested inside each other, allowing complex data structures like arrays of objects or objects containing arrays.

Here, We are providing a list of examples of JSON data.

1. JSON data example with simple employee object:

				
					{
    "name": "Alice",
    "age": 25,
    "city": "New York"
}

2. JSON data example Employee object with nested address:

				
					{
    "id": 2,
    "name": "Jane Smith",
    "position": "HR Manager",
    "department": "Human Resources",
    "salary": 68000,
    "address": {
        "street": "123 Elm Street",
        "city": "Los Angeles",
        "state": "CA",
        "zipcode": "90001"
    }
}

3.JSON data example employee object with skills array:

				
					{
    "id": 3,
    "name": "Emily Johnson",
    "position": "Data Analyst",
    "department": "Analytics",
    "skills": ["Excel", "SQL", "Python", "Tableau"],
    "fullTime": true
}

4.JSON data example list of multiple employees (array of objects):

				
					[
    {
        "id": 4,
        "name": "Michael Brown",
        "position": "Project Manager",
        "department": "Operations"
    },
    {
        "id": 5,
        "name": "Laura Wilson",
        "position": "UX Designer",
        "department": "Design"
    }
]

5.JSON data example Detailed employee with joining date and reporting manager:

				
					{
    "id": 6,
    "name": "Chris Evans",
    "position": "Marketing Lead",
    "department": "Marketing",
    "joiningDate": "2022-08-15",
    "reportingManager": "Sarah Connor"
}

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