Create an array filled with ones and having the same length and data type as a provided array.
npm install @stdlib/array-ones-likeWe 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]
> Create an array filled with ones and having the same length and data type as a provided array.
``bash`
npm install @stdlib/array-ones-like
`javascript`
var onesLike = require( '@stdlib/array-ones-like' );
#### onesLike( x\[, dtype] )
Creates an array filled with ones and having the same length and data type as a provided array x.
`javascript
var x = [ 1, 2, 3, 4, 5 ];
var arr = onesLike( x );
// returns [ 1, 1, 1, 1, 1 ]
`
The function supports the following data types:
- float64: double-precision floating-point numbers (IEEE 754)float32
- : single-precision floating-point numbers (IEEE 754)complex128
- : double-precision complex floating-point numberscomplex64
- : single-precision complex floating-point numbersint32
- : 32-bit two's complement signed integersuint32
- : 32-bit unsigned integersint16
- : 16-bit two's complement signed integersuint16
- : 16-bit unsigned integersint8
- : 8-bit two's complement signed integersuint8
- : 8-bit unsigned integersuint8c
- : 8-bit unsigned integers clamped to 0-255
- : generic JavaScript values
By default, the output array data type is inferred from the provided array x. To return an array having a different data type, provide a dtype argument.
`javascript
var x = [ 0, 0 ];
var arr = onesLike( x, 'int32' );
// returns
`
- If the output array has a complex number data type, each element of the returned array has a real component equal to 1 and an imaginary component equal to 0.
`javascript
var dtypes = require( '@stdlib/array-dtypes' );
var zeros = require( '@stdlib/array-zeros' );
var onesLike = require( '@stdlib/array-ones-like' );
// Create a zero-filled array:
var x = zeros( 4, 'complex128' );
// Get a list of array data types:
var dt = dtypes();
// Generate filled arrays...
var y;
var i;
for ( i = 0; i < dt.length; i++ ) {
y = onesLike( x, dt[ i ] );
console.log( y );
}
`
*
- [@stdlib/array-full-like][@stdlib/array/full-like]: create a filled array having the same length and data type as a provided array.
- [@stdlib/array-nans-like][@stdlib/array/nans-like]: create an array filled with NaNs and having the same length and data type as a provided array.
- [@stdlib/array-ones][@stdlib/array/ones]: create an array filled with ones and having a specified length.
- [@stdlib/array-zeros-like][@stdlib/array/zeros-like]: create a zero-filled array having the same length and data type as a provided array.
*
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].
[npm-image]: http://img.shields.io/npm/v/@stdlib/array-ones-like.svg
[npm-url]: https://npmjs.org/package/@stdlib/array-ones-like
[test-image]: https://github.com/stdlib-js/array-ones-like/actions/workflows/test.yml/badge.svg?branch=v0.2.2
[test-url]: https://github.com/stdlib-js/array-ones-like/actions/workflows/test.yml?query=branch:v0.2.2
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/array-ones-like/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/array-ones-like?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
[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/array-ones-like/tree/deno
[deno-readme]: https://github.com/stdlib-js/array-ones-like/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/array-ones-like/tree/umd
[umd-readme]: https://github.com/stdlib-js/array-ones-like/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/array-ones-like/tree/esm
[esm-readme]: https://github.com/stdlib-js/array-ones-like/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/array-ones-like/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/array-ones-like/main/LICENSE
[@stdlib/array/full-like]: https://www.npmjs.com/package/@stdlib/array-full-like
[@stdlib/array/nans-like]: https://www.npmjs.com/package/@stdlib/array-nans-like
[@stdlib/array/ones]: https://www.npmjs.com/package/@stdlib/array-ones
[@stdlib/array/zeros-like]: https://www.npmjs.com/package/@stdlib/array-zeros-like