npm package: @stdlib/fs-read-json
Description: Read a file as JSON.
Author: The Stdlib Authors
Latest version: 0.2.4

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<details>
  <summary>
    About stdlib...
  </summary>
  <p>We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.</p>
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</details>

# Read JSON

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Read a file as [JSON][json].

<section class="installation">

## Installation

```bash
npm install @stdlib/fs-read-json
```

</section>

<section class="usage">

## Usage

```javascript
var readJSON = require( '@stdlib/fs-read-json' );
```

<a name="read-json"></a>

#### readJSON( file\[, options], clbk )

Asynchronously reads a file as [JSON][json].

```javascript
var join = require( 'path' ).join;

readJSON( join( __dirname, 'package.json' ), onJSON );

function onJSON( error, data ) {
    if ( error ) {
        throw error;
    }
    console.dir( data );
}
```

The function accepts the following `options`:

-   **encoding**: file encoding.
-   **flag**: file status flag.
-   **reviver**: [JSON][json] transformation `function`.

The `options` parameter may also be a `string` specifying the file `encoding`.

```javascript
var join = require( 'path' ).join;

readJSON( join( __dirname, 'package.json' ), 'utf8', onJSON );

function onJSON( error, data ) {
    if ( error ) {
        throw error;
    }
    console.dir( data );
}
```

#### readJSON.sync( file\[, options] )

Synchronously reads a file as [JSON][json].

```javascript
var join = require( 'path' ).join;
var instanceOf = require( '@stdlib/assert-instance-of' );

var out = readJSON.sync( join( __dirname, 'package.json' ) );
if ( instanceOf( out, Error ) ) {
    throw out;
}
console.dir( out );
```

The function accepts the same `options` as [`readJSON()`](#read-json) above.

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   If the `encoding` option is set to `utf8` and the file has a UTF-8 [byte order mark][bom] (BOM), the byte order mark is **removed** before attempting to parse as [JSON][json].

</section>

<!-- /.notes -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var join = require( 'path' ).join;
var readJSON = require( '@stdlib/fs-read-json' );

var file = join( __dirname, 'package.json' );

// Synchronously read file contents...
var data = readJSON.sync( file, 'utf8' );
// returns <Object>

data = readJSON.sync( 'beepboop', {
    'encoding': 'utf8'
});
// returns <Error>

// Asynchronously read file contents...
readJSON( file, onJSON );
readJSON( 'beepboop', onJSON );

function onJSON( error, data ) {
    if ( error ) {
        if ( error.code === 'ENOENT' ) {
            console.error( 'JSON file does not exist.' );
        } else {
            throw error;
        }
    } else {
        console.log( 'Package description: %s', data.description );
    }
}
```

</section>

<!-- /.examples -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/fs-read-file`][@stdlib/fs/read-file]</span><span class="delimiter">: </span><span class="description">read the entire contents of a file.</span>

</section>

<!-- /.related -->

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<section class="main-repo" >

* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

</section>

<!-- /.stdlib -->

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[npm-url]: https://npmjs.org/package/@stdlib/fs-read-json

[test-image]: https://github.com/stdlib-js/fs-read-json/actions/workflows/test.yml/badge.svg?branch=v0.2.4
[test-url]: https://github.com/stdlib-js/fs-read-json/actions/workflows/test.yml?query=branch:v0.2.4

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/fs-read-json/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/fs-read-json?branch=main

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[stdlib]: https://github.com/stdlib-js/stdlib

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[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

[deno-url]: https://github.com/stdlib-js/fs-read-json/tree/deno
[deno-readme]: https://github.com/stdlib-js/fs-read-json/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/fs-read-json/tree/umd
[umd-readme]: https://github.com/stdlib-js/fs-read-json/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/fs-read-json/tree/esm
[esm-readme]: https://github.com/stdlib-js/fs-read-json/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/fs-read-json/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/fs-read-json/main/LICENSE

[json]: http://www.json.org/

[bom]: https://en.wikipedia.org/wiki/Byte_order_mark

<!-- <related-links> -->

[@stdlib/fs/read-file]: https://www.npmjs.com/package/@stdlib/fs-read-file

<!-- </related-links> -->

</section>

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