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JSON Format Specification & Converter Info

JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate. It is based on a subset of the JavaScript Programming Language Standard ECMA-262 3rd Edition - December 1999.

Introduction

JSON is a text format that is completely language independent but uses conventions that are familiar to programmers of the C-family of languages, including C, C++, C#, Java, JavaScript, Perl, Python, and many others. These properties make JSON an ideal data-interchange language.

Key Features

  • Lightweight: JSON has a small footprint, making it ideal for data transmission over networks.
  • Human-Readable: The syntax is simple and easy to understand.
  • Language Independent: Supported by virtually all modern programming languages.
  • Self-Describing: The structure of the data is evident from the format itself.

Syntax

JSON is built on two structures:

  1. A collection of name/value pairs. In various languages, this is realized as an object, record, struct, dictionary, hash table, keyed list, or associative array.
  2. An ordered list of values. In most languages, this is realized as an array, vector, list, or sequence.

Example

{
  "name": "John Doe",
  "age": 30,
  "isStudent": false,
  "courses": ["Math", "Computer Science"],
  "address": {
    "street": "123 Main St",
    "city": "Anytown"
  }
}

Data Types

JSON supports the following data types:

  • String: A sequence of Unicode characters, enclosed in double quotes.
  • Number: Integer or floating-point numbers.
  • Boolean: true or false.
  • Null: Represents an empty value, written as null.
  • Object: An unordered collection of key/value pairs, enclosed in curly braces {}.
  • Array: An ordered list of values, enclosed in square brackets [].

Use Cases

  • Web APIs: The de facto standard for data exchange in RESTful APIs.
  • Configuration Files: Used for configuring applications (e.g., package.json, tsconfig.json).
  • Data Storage: NoSQL databases like MongoDB use JSON-like formats (BSON) for storage.

Related Formats

Compare JSON with other data formats:

  • TOON (Token-Oriented Object Notation) - Optimized for LLMs to save tokens.
  • YAML - Often used for configuration files where human readability is paramount.
  • XML - A markup language with a strict syntax, often used in enterprise systems.
  • TOML - A minimal configuration file format.

Resources