npm package: @stdlib/array-base-fill
Description: Fill all elements within a portion of an array with a specified value.
Author: The Stdlib Authors
Latest version: 0.1.1

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<details>
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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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# fill

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

> Fill all elements within a portion of an array with a specified value.

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<section class="intro">

</section>

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<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/array-base-fill
```

</section>

<section class="usage">

## Usage

```javascript
var fill = require( '@stdlib/array-base-fill' );
```

#### fill( x, value, start, end )

Fills all elements within a portion of an array from an inclusive `start` index to an exclusive `end` index with a specified `value`.

```javascript
var x = [ 1, 2, 3, 4, 5, 6 ];

var out = fill( x, 10, 1, 4 );
// returns [ 1, 10, 10, 10, 5, 6 ]

var bool = ( out === x );
// returns true
```

</section>

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<!-- 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 provided an array-like object having a `fill` method, the function defers execution to that method and assumes that the method API has the following signature:

    ```text
    x.fill( value, start, end )
    ```

-   If provided an array-like object without a `fill` method, the function manually sets input array elements to a provided fill value.

-   Negative `start` and `end` indices are resolved to positive indices by counting from the end of the array with `-1` corresponding to the last indexed element.

-   The function **mutates** the input array.

</section>

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<!-- Package usage examples. -->

<section class="examples">

## Examples

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

```javascript
var Float64Array = require( '@stdlib/array-float64' );
var zeroTo = require( '@stdlib/array-base-zero-to' );
var fill = require( '@stdlib/array-base-fill' );

var x = new Float64Array( zeroTo( 6 ) );
// returns <Float64Array>[ 0.0, 1.0, 2.0, 3.0, 4.0, 5.0 ]

var y = fill( x, 10.0, 0, 6 );
// returns <Float64Array>[ 10.0, 10.0, 10.0, 10.0, 10.0, 10.0 ]

y = fill( x, 0.0, 0, 4 );
// returns <Float64Array>[ 0.0, 0.0, 0.0, 0.0, 10.0, 10.0 ]

y = fill( x, 20.0, 2, 6 );
// returns <Float64Array>[ 0.0, 0.0, 20.0, 20.0, 20.0, 20.0 ]

y = fill( x, 30.0, 2, 4 );
// returns <Float64Array>[ 0.0, 0.0, 30.0, 30.0, 20.0, 20.0 ]
```

</section>

<!-- /.examples -->

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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-url]: https://npmjs.org/package/@stdlib/array-base-fill

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[test-url]: https://github.com/stdlib-js/array-base-fill/actions/workflows/test.yml?query=branch:v0.1.1

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[umd]: https://github.com/umdjs/umd
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[branches-url]: https://github.com/stdlib-js/array-base-fill/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/array-base-fill/main/LICENSE

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