npm package: @stdlib/array-ones-like
Description: Create an array filled with ones and having the same length and data type as a provided array.
Author: The Stdlib Authors
Latest version: 0.2.2

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<details>
  <summary>
    About stdlib...
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  <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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# onesLike

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

> Create an array filled with ones and having the same length and data type as a provided array.

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

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<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/array-ones-like
```

</section>

<section class="usage">

## Usage

```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 numbers
-   `complex64`: single-precision complex floating-point numbers
-   `int32`: 32-bit two's complement signed integers
-   `uint32`: 32-bit unsigned integers
-   `int16`: 16-bit two's complement signed integers
-   `uint16`: 16-bit unsigned integers
-   `int8`: 8-bit two's complement signed integers
-   `uint8`: 8-bit unsigned integers
-   `uint8c`: 8-bit unsigned integers clamped to `0-255`
-   `generic`: 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 <Int32Array>[ 1, 1 ]
```

</section>

<!-- /.usage -->

<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

## Notes

-   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`.

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

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

```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 );
}
```

</section>

<!-- /.examples -->

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</section>

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<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/array-full-like`][@stdlib/array/full-like]</span><span class="delimiter">: </span><span class="description">create a filled array having the same length and data type as a provided array.</span>
-   <span class="package-name">[`@stdlib/array-nans-like`][@stdlib/array/nans-like]</span><span class="delimiter">: </span><span class="description">create an array filled with NaNs and having the same length and data type as a provided array.</span>
-   <span class="package-name">[`@stdlib/array-ones`][@stdlib/array/ones]</span><span class="delimiter">: </span><span class="description">create an array filled with ones and having a specified length.</span>
-   <span class="package-name">[`@stdlib/array-zeros-like`][@stdlib/array/zeros-like]</span><span class="delimiter">: </span><span class="description">create a zero-filled array having the same length and data type as a provided array.</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>

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[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
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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/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

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

[@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

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</section>

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