json5 vs strip-json-comments vs hjson
JSON Parsing and Manipulation Comparison
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json5strip-json-commentshjsonSimilar Packages:
What's JSON Parsing and Manipulation?

JSON Parsing and Manipulation libraries in JavaScript provide tools for working with JSON (JavaScript Object Notation) data, which is a widely used format for data interchange. These libraries offer features for parsing JSON strings into JavaScript objects, serializing objects into JSON format, and manipulating JSON data with greater flexibility and ease. They often include enhancements over the native JSON methods, such as better handling of comments, support for non-standard syntax, and more customizable serialization options. This makes them valuable for web development, APIs, and any application that interacts with JSON data.

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json5126,701,6436,898235 kB36-MIT
strip-json-comments107,941,0416098.15 kB1a month agoMIT
hjson314,454422-255 years agoMIT
Feature Comparison: json5 vs strip-json-comments vs hjson

Comment Support

  • json5:

    json5 also supports comments, including single-line and multi-line comments. This feature allows for better documentation and clarity within JSON5 files, making them easier to understand.

  • strip-json-comments:

    strip-json-comments is specifically designed to remove comments from JSON strings. It does not support comments itself but provides a way to strip them out, ensuring the resulting JSON is valid.

  • hjson:

    hjson supports comments natively, allowing both single-line (//) and multi-line (/* ... */) comments. This makes it easy to document your data directly within the file without any additional processing.

Syntax Flexibility

  • json5:

    json5 is a superset of JSON that allows for unquoted keys, trailing commas, and more lenient parsing. This makes it more forgiving and easier to work with, especially when dealing with large or complex data structures.

  • strip-json-comments:

    strip-json-comments does not alter the syntax of JSON; it simply removes comments. It is a lightweight tool that ensures your JSON remains compliant while allowing you to include comments during development.

  • hjson:

    hjson offers a more relaxed syntax compared to standard JSON, allowing for features like multi-line strings, unquoted keys, and more. This flexibility makes it easier to write and read, especially for configuration files.

Use Case

  • json5:

    json5 is suitable for any application that can benefit from a more flexible JSON format, including configuration files, data serialization, and APIs that can handle the extended syntax.

  • strip-json-comments:

    strip-json-comments is perfect for preprocessing JSON files or strings that contain comments, making it useful for projects that want to maintain standard JSON compliance while allowing comments in the source files.

  • hjson:

    hjson is ideal for configuration files, data interchange where readability is important, and scenarios where you want to allow more human-friendly input while still being able to convert to standard JSON.

Example Code

  • json5:

    Example of json5 with comments and flexible syntax:

    {
      // This is a comment
      name: "Jane Doe", // Unquoted key
      age: 25,
      hobbies: [
        "painting",
        "traveling",
        "music",
        // Trailing comma
      ],
      address: {
        street: "456 Elm St",
        city: "Othertown",
        zip: "67890",
      }
    }
    
  • strip-json-comments:

    Example of using strip-json-comments to remove comments:

    const stripJsonComments = require('strip-json-comments');
    
    const jsonWithComments = `{
      // This is a comment
      "name": "Alice", // Inline comment
      "age": 28,
      "hobbies": [
        "drawing",
        "cycling" // Another comment
      ]
      /* Multi-line comment */
    }`;
    
    const jsonWithoutComments = stripJsonComments(jsonWithComments);
    console.log(jsonWithoutComments);
    // Output:
    // {
    //   "name": "Alice",
    //   "age": 28,
    //   "hobbies": [
    //     "drawing",
    //     "cycling"
    //   ]
    // }
    
  • hjson:

    Example of hjson with comments and relaxed syntax:

    {
      // This is a comment
      name: "John Doe",  // Inline comment
      age: 30,
      hobbies: [
        "reading",
        /* This is a multi-line comment
           that explains the hobbies
        */
        "hiking",
        "coding"
      ],
      address: {
        street: "123 Main St",
        city: "Anytown",
        zip: "12345"
      }
    }
    
How to Choose: json5 vs strip-json-comments vs hjson
  • json5:

    Select json5 if you want to work with a superset of JSON that allows for comments, trailing commas, and unquoted keys, making it more flexible and forgiving than standard JSON. It is great for projects that require a more lenient syntax while maintaining compatibility with JSON.

  • strip-json-comments:

    Use strip-json-comments if you only need to remove comments from JSON strings before parsing them. This lightweight package is perfect for situations where you want to keep your JSON files standard-compliant but still want to include comments for documentation purposes.

  • hjson:

    Choose hjson if you need a human-friendly JSON format that supports comments, multi-line strings, and more relaxed syntax while still being easily convertible to standard JSON. It is ideal for configuration files and scenarios where readability is a priority.

README for json5

JSON5 – JSON for Humans

Build Status Coverage
Status

JSON5 is an extension to the popular JSON file format that aims to be easier to write and maintain by hand (e.g. for config files). It is not intended to be used for machine-to-machine communication. (Keep using JSON or other file formats for that. 🙂)

JSON5 was started in 2012, and as of 2022, now gets >65M downloads/week, ranks in the top 0.1% of the most depended-upon packages on npm, and has been adopted by major projects like Chromium, Next.js, Babel, Retool, WebStorm, and more. It's also natively supported on Apple platforms like MacOS and iOS.

Formally, the JSON5 Data Interchange Format is a superset of JSON (so valid JSON files will always be valid JSON5 files) that expands its syntax to include some productions from ECMAScript 5.1 (ES5). It's also a strict subset of ES5, so valid JSON5 files will always be valid ES5.

This JavaScript library is a reference implementation for JSON5 parsing and serialization, and is directly used in many of the popular projects mentioned above (where e.g. extreme performance isn't necessary), but others have created many other libraries across many other platforms.

Summary of Features

The following ECMAScript 5.1 features, which are not supported in JSON, have been extended to JSON5.

Objects

  • Object keys may be an ECMAScript 5.1 IdentifierName.
  • Objects may have a single trailing comma.

Arrays

  • Arrays may have a single trailing comma.

Strings

  • Strings may be single quoted.
  • Strings may span multiple lines by escaping new line characters.
  • Strings may include character escapes.

Numbers

  • Numbers may be hexadecimal.
  • Numbers may have a leading or trailing decimal point.
  • Numbers may be IEEE 754 positive infinity, negative infinity, and NaN.
  • Numbers may begin with an explicit plus sign.

Comments

  • Single and multi-line comments are allowed.

White Space

  • Additional white space characters are allowed.

Example

Kitchen-sink example:

{
  // comments
  unquoted: 'and you can quote me on that',
  singleQuotes: 'I can use "double quotes" here',
  lineBreaks: "Look, Mom! \
No \\n's!",
  hexadecimal: 0xdecaf,
  leadingDecimalPoint: .8675309, andTrailing: 8675309.,
  positiveSign: +1,
  trailingComma: 'in objects', andIn: ['arrays',],
  "backwardsCompatible": "with JSON",
}

A more real-world example is this config file from the Chromium/Blink project.

Specification

For a detailed explanation of the JSON5 format, please read the official specification.

Installation and Usage

Node.js

npm install json5

CommonJS

const JSON5 = require('json5')

Modules

import JSON5 from 'json5'

Browsers

UMD

<!-- This will create a global `JSON5` variable. -->
<script src="https://unpkg.com/json5@2/dist/index.min.js"></script>

Modules

<script type="module">
  import JSON5 from 'https://unpkg.com/json5@2/dist/index.min.mjs'
</script>

API

The JSON5 API is compatible with the JSON API.

JSON5.parse()

Parses a JSON5 string, constructing the JavaScript value or object described by the string. An optional reviver function can be provided to perform a transformation on the resulting object before it is returned.

Syntax

JSON5.parse(text[, reviver])

Parameters

  • text: The string to parse as JSON5.
  • reviver: If a function, this prescribes how the value originally produced by parsing is transformed, before being returned.

Return value

The object corresponding to the given JSON5 text.

JSON5.stringify()

Converts a JavaScript value to a JSON5 string, optionally replacing values if a replacer function is specified, or optionally including only the specified properties if a replacer array is specified.

Syntax

JSON5.stringify(value[, replacer[, space]])
JSON5.stringify(value[, options])

Parameters

  • value: The value to convert to a JSON5 string.
  • replacer: A function that alters the behavior of the stringification process, or an array of String and Number objects that serve as a whitelist for selecting/filtering the properties of the value object to be included in the JSON5 string. If this value is null or not provided, all properties of the object are included in the resulting JSON5 string.
  • space: A String or Number object that's used to insert white space into the output JSON5 string for readability purposes. If this is a Number, it indicates the number of space characters to use as white space; this number is capped at 10 (if it is greater, the value is just 10). Values less than 1 indicate that no space should be used. If this is a String, the string (or the first 10 characters of the string, if it's longer than that) is used as white space. If this parameter is not provided (or is null), no white space is used. If white space is used, trailing commas will be used in objects and arrays.
  • options: An object with the following properties:
    • replacer: Same as the replacer parameter.
    • space: Same as the space parameter.
    • quote: A String representing the quote character to use when serializing strings.

Return value

A JSON5 string representing the value.

Node.js require() JSON5 files

When using Node.js, you can require() JSON5 files by adding the following statement.

require('json5/lib/register')

Then you can load a JSON5 file with a Node.js require() statement. For example:

const config = require('./config.json5')

CLI

Since JSON is more widely used than JSON5, this package includes a CLI for converting JSON5 to JSON and for validating the syntax of JSON5 documents.

Installation

npm install --global json5

Usage

json5 [options] <file>

If <file> is not provided, then STDIN is used.

Options:

  • -s, --space: The number of spaces to indent or t for tabs
  • -o, --out-file [file]: Output to the specified file, otherwise STDOUT
  • -v, --validate: Validate JSON5 but do not output JSON
  • -V, --version: Output the version number
  • -h, --help: Output usage information

Contributing

Development

git clone https://github.com/json5/json5
cd json5
npm install

When contributing code, please write relevant tests and run npm test and npm run lint before submitting pull requests. Please use an editor that supports EditorConfig.

Issues

To report bugs or request features regarding the JSON5 data format, please submit an issue to the official specification repository.

Note that we will never add any features that make JSON5 incompatible with ES5; that compatibility is a fundamental premise of JSON5.

To report bugs or request features regarding this JavaScript implementation of JSON5, please submit an issue to this repository.

Security Vulnerabilities and Disclosures

To report a security vulnerability, please follow the follow the guidelines described in our security policy.

License

MIT. See LICENSE.md for details.

Credits

Aseem Kishore founded this project. He wrote a blog post about the journey and lessons learned 10 years in.

Michael Bolin independently arrived at and published some of these same ideas with awesome explanations and detail. Recommended reading: Suggested Improvements to JSON

Douglas Crockford of course designed and built JSON, but his state machine diagrams on the JSON website, as cheesy as it may sound, gave us motivation and confidence that building a new parser to implement these ideas was within reach! The original implementation of JSON5 was also modeled directly off of Doug’s open-source json_parse.js parser. We’re grateful for that clean and well-documented code.

Max Nanasy has been an early and prolific supporter, contributing multiple patches and ideas.

Andrew Eisenberg contributed the original stringify method.

Jordan Tucker has aligned JSON5 more closely with ES5, wrote the official JSON5 specification, completely rewrote the codebase from the ground up, and is actively maintaining this project.