🚀 Json parser in mighty php

Overview

A simple JSON parser implementation in PHP that parses JSON strings into PHP data structures. This project demonstrates how to build a JSON parser from scratch without relying on PHP's built-in json_decode() function.

If you like to build your own JSON parser and you need to understand how it works, this project is for you.

Features

• ✅ Complete JSON compliance - Passes the official JSON.org test suite
• ✅ Full data type support:
  • Strings with escape sequences (\", \\, \/, \b, \f, \n, \r, \t)
  • Numbers (integers, floats, scientific notation: 1e3, 5.5e-1)
  • Booleans (true/false)
  • null values
  • Arrays (nested and empty)
  • Objects (nested and empty)
• ✅ Advanced string parsing:
  • Unicode escape sequences (\uXXXX)
  • Control character validation (prevents unescaped control chars)
• ✅ Robust number validation:
  • Prevents invalid leading zeros (e.g., 013)
  • Supports scientific notation (1e3, 2e+00, 5.5e-1)
  • Handles negative numbers and decimals

Installation

Prerequisites

• PHP 8.4+
• Composer

Local Setup

1. Clone the repository:

git clone https://github.com/DanielHemmati/json-parser-in-php
cd json-parser-in-php

2. Install dependencies:

composer install

3. Run the tests:

./vendor/bin/pest

Contributing

Contributions are welcome! Please feel free to submit a pull request.

Todos

• Add benchmark to the project. (thanks to @mamazu)
• Add suppport for not loading all of the json into memory at once (see read json-machine for study, also mlebkowski showed his parser Good place to get deeper into parser)
• Add pint & phpstan

License

This project is licensed under the MIT License - see the LICENSE file for details.