Platform byte order.
npm install @stdlib/os-byte-orderWe 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. The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases. When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there. To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!
About stdlib...
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
> Platform [byte order][endianness].
``bash`
npm install @stdlib/os-byte-order
`javascript`
var BYTE_ORDER = require( '@stdlib/os-byte-order' );
#### BYTE_ORDER
Platform byte order.
`javascript`
console.log( BYTE_ORDER );
// =>
- The following values are possible:
- 'little-endian'
-
- (also known as "middle-endian")'unknown'
-
`javascript
var BYTE_ORDER = require( '@stdlib/os-byte-order' );
if ( BYTE_ORDER === 'little-endian' ) {
console.log( 'Least significant byte comes first...' );
} else if ( BYTE_ORDER === 'big-endian' ) {
console.log( 'Most significant byte comes first...' );
} else {
console.log( 'This is uncommon...' );
}
`
*
`c`
#include "stdlib/os/byte_order.h"
#### STDLIB_OS_ORDER_LITTLE_ENDIAN
Macro for an arbitrary constant indicating little-endian order.
`c
#if defined(STDLIB_OS_BYTE_ORDER) && STDLIB_OS_BYTE_ORDER == STDLIB_OS_ORDER_LITTLE_ENDIAN
// Do something for little-endian...
#endif
`
If compiled on an unrecognized/unsupported platform, the macro is not defined.
#### STDLIB_OS_ORDER_BIG_ENDIAN
Macro for an arbitrary constant indicating big-endian order.
`c
#if defined(STDLIB_OS_BYTE_ORDER) && STDLIB_OS_BYTE_ORDER == STDLIB_OS_ORDER_BIG_ENDIAN
// Do something for big-endian...
#endif
`
If compiled on an unrecognized/unsupported platform, the macro is not defined.
#### STDLIB_OS_BYTE_ORDER
Macro which equals either STDLIB_OS_ORDER_LITTLE_ENDIAN or STDLIB_OS_ORDER_BIG_ENDIAN (or host defined) depending on the resolved platform byte order.
`c
#if defined(STDLIB_OS_BYTE_ORDER)
#if STDLIB_OS_BYTE_ORDER == STDLIB_OS_ORDER_LITTLE_ENDIAN
// Do something for little-endian...
#elif STDLIB_OS_BYTE_ORDER == STDLIB_OS_ORDER_BIG_ENDIAN
// Do something for big-endian...
#endif
#endif
`
If compiled on an unrecognized/unsupported platform, the macro is not defined.
`c
#include "stdlib/os/byte_order.h"
#include
int main( void ) {
#if defined(STDLIB_OS_BYTE_ORDER)
#if STDLIB_OS_BYTE_ORDER == STDLIB_OS_ORDER_LITTLE_ENDIAN
printf( "Platform is little-endian...\n" );
#elif STDLIB_OS_BYTE_ORDER == STDLIB_OS_ORDER_BIG_ENDIAN
printf( "Platform is big-endian...\n" );
#else
printf( "Platform endianness is either mixed-endian or unknown...\n" )
#endif
#endif
}
`
- [@stdlib/os-byte-order-cli][@stdlib/os-byte-order-cli]: CLI package for use as a command-line utility.
- [@stdlib/assert-is-big-endian][@stdlib/assert/is-big-endian]: check if an environment is big endian.
- [@stdlib/assert-is-little-endian][@stdlib/assert/is-little-endian]: check if an environment is little endian.
*
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]
---
See [LICENSE][stdlib-license].
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
[@stdlib/os-byte-order-cli]: https://www.npmjs.com/package/@stdlib/os-byte-order-cli
[npm-image]: http://img.shields.io/npm/v/@stdlib/os-byte-order.svg
[npm-url]: https://npmjs.org/package/@stdlib/os-byte-order
[test-image]: https://github.com/stdlib-js/os-byte-order/actions/workflows/test.yml/badge.svg?branch=v0.2.3
[test-url]: https://github.com/stdlib-js/os-byte-order/actions/workflows/test.yml?query=branch:v0.2.3
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/os-byte-order/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/os-byte-order?branch=main
[chat-image]: https://img.shields.io/badge/zulip-join_chat-brightgreen.svg
[chat-url]: https://stdlib.zulipchat.com
[stdlib]: https://github.com/stdlib-js/stdlib
[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors
[cli-section]: https://github.com/stdlib-js/os-byte-order#cli
[cli-url]: https://github.com/stdlib-js/os-byte-order/tree/cli
[@stdlib/os-byte-order]: https://github.com/stdlib-js/os-byte-order/tree/main
[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/os-byte-order/tree/deno
[deno-readme]: https://github.com/stdlib-js/os-byte-order/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/os-byte-order/tree/umd
[umd-readme]: https://github.com/stdlib-js/os-byte-order/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/os-byte-order/tree/esm
[esm-readme]: https://github.com/stdlib-js/os-byte-order/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/os-byte-order/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/os-byte-order/main/LICENSE
[endianness]: https://en.wikipedia.org/wiki/Endianness
[@stdlib/assert/is-big-endian]: https://www.npmjs.com/package/@stdlib/assert-is-big-endian
[@stdlib/assert/is-little-endian]: https://www.npmjs.com/package/@stdlib/assert-is-little-endian