npm package: @stdlib/utils-argument-function
Description: Argument function.
Author: The Stdlib Authors
Latest version: 0.2.3

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    About stdlib...
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# Argument Function

[![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 argument function.

<section class="intro">

</section>

<!-- /.intro -->

<section class="installation">

## Installation

```bash
npm install @stdlib/utils-argument-function
```

</section>

<section class="usage">

## Usage

```javascript
var argumentFunction = require( '@stdlib/utils-argument-function' );
```

#### argumentFunction( idx )

Returns a `function` which always returns an argument corresponding to a specified argument index.

```javascript
var argn = argumentFunction( 1 );
// returns <Function>

var v = argn( 1.0, 2.0, 3.0 );
// returns 2.0

v = argn( 'a', 'b', 'c' );
// returns 'b'
```

If an argument function is provided fewer arguments than the specified argument index, an argument function returns `undefined`.

```javascript
var argn = argumentFunction( 100 );
// returns <Function>

var v = argn( 1.0 );
// returns undefined
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   Argument indices are **zero-based**.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var randu = require( '@stdlib/random-base-randu' );
var argumentFunction = require( '@stdlib/utils-argument-function' );

var argn;
var v;
var i;

argn = argumentFunction( 1 );
for ( i = 0; i < 10; i++ ) {
    v = argn( randu(), randu()*10.0, randu()*100.0 );
    console.log( v );
}
```

</section>

<!-- /.examples -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/utils-constant-function`][@stdlib/utils/constant-function]</span><span class="delimiter">: </span><span class="description">constant function.</span>
-   <span class="package-name">[`@stdlib/utils-identity-function`][@stdlib/utils/identity-function]</span><span class="delimiter">: </span><span class="description">identity function.</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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[test-image]: https://github.com/stdlib-js/utils-argument-function/actions/workflows/test.yml/badge.svg?branch=v0.2.3
[test-url]: https://github.com/stdlib-js/utils-argument-function/actions/workflows/test.yml?query=branch:v0.2.3

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/utils-argument-function/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/utils-argument-function?branch=main

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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/utils-argument-function/tree/deno
[deno-readme]: https://github.com/stdlib-js/utils-argument-function/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/utils-argument-function/tree/umd
[umd-readme]: https://github.com/stdlib-js/utils-argument-function/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/utils-argument-function/tree/esm
[esm-readme]: https://github.com/stdlib-js/utils-argument-function/blob/esm/README.md
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[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/utils-argument-function/main/LICENSE

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

[@stdlib/utils/constant-function]: https://www.npmjs.com/package/@stdlib/utils-constant-function

[@stdlib/utils/identity-function]: https://www.npmjs.com/package/@stdlib/utils-identity-function

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</section>

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