JSON (JavaScript Object Notation) is a lightweight data interchange format. Its syntax is simple yet powerful, making it easy for humans to read and write, and for machines to parse and generate.

Basic Structure

JSON data is built on two primary structures:

A collection of name/value pairs (realized as an JSON object)
An ordered list of values (realized as an JSON array)

JSON Object

An object is enclosed in curly braces {} and contains key-value pairs. Each key is a string, followed by a colon, and then the value.

{
  "name": "John Doe",
  "age": 30,
  "city": "New York"
}

JSON Array

An array is an ordered collection of values, enclosed in square brackets [].

["apple", "banana", "cherry"]

Data Types

JSON supports several data types:

String: A sequence of characters in double quotes
Number: Integer or floating-point
Boolean: true or false
Null: Represents a null value
Object: A collection of key-value pairs
Array: An ordered list of values

Nesting

JSON supports nesting of objects and arrays, allowing for complex data structures.

{
  "person": {
    "name": "Alice",
    "hobbies": ["reading", "cycling"]
  }
}

Important Considerations

JSON is case-sensitive
Keys must be strings and use double quotes
Trailing commas are not allowed
Comments are not supported in standard JSON

Parsing and Stringification

Most programming languages provide built-in functions for parsing JSON strings into native data structures and stringifying data structures into JSON format.

Conclusion

Understanding JSON syntax is crucial for working with modern web APIs and data interchange. Its simplicity and flexibility make it a popular choice for data serialization across various programming languages and platforms.