Read a file as JSON.
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> Read a file as [JSON][json].
``bash`
npm install @stdlib/fs-read-json
`javascript`
var readJSON = require( '@stdlib/fs-read-json' );
#### 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() above.
- 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].
`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
data = readJSON.sync( 'beepboop', {
'encoding': 'utf8'
});
// returns
// 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 );
}
}
`
*
- [@stdlib/fs-read-file][@stdlib/fs/read-file]: read the entire contents of a file.
*
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].
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---
See [LICENSE][stdlib-license].
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
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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
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[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
[@stdlib/fs/read-file]: https://www.npmjs.com/package/@stdlib/fs-read-file