npm package: @stdlib/utils-nary-function
Description: Create a function that invokes a provided function with a specified number of arguments.
Author: The Stdlib Authors
Latest version: 0.2.4

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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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# naryFunction

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

> Create a function that invokes a provided function with a specified number of arguments.

<!-- 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>

<!-- /.intro -->

<!-- Package usage documentation. -->

<section class="installation">

## Installation

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

</section>

<section class="usage">

## Usage

```javascript
var naryFunction = require( '@stdlib/utils-nary-function' );
```

#### naryFunction( fcn, arity\[, thisArg] )

Returns a `function` that invokes a provided function with a specified number of arguments.

```javascript
function sum() {
    var s;
    var i;

    s = 0;
    for ( i = 0; i < arguments.length; i++ ) {
        s += arguments[ i ];
    }
    return s;
}

var fcn = naryFunction( sum, 2 );

var out = fcn( -1, -2, 3 );
// returns -3
```

To set the `this` context when invoking the provided function, provide a `thisArg`.

<!-- eslint-disable no-restricted-syntax -->

```javascript
function Foo() {
    this.scalar = 1;
}

Foo.prototype.sum = function sum() {
    var s;
    var i;

    s = 0;
    for ( i = 0; i < arguments.length; i++ ) {
        s += arguments[ i ] * this.scalar;
    }
    return s;
};

var ctx = {
    'scalar': 3
};

var foo = new Foo();

var fcn = naryFunction( foo.sum, 2, ctx );

var out = fcn( 1, 2, 3 );
// returns 9
```

</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

-   The returned function **always** invokes the wrapped function with a specified number of arguments, even when the returned function is provided fewer arguments. The value for the missing arguments is equal to `undefined`.

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

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

```javascript
var filledarrayBy = require( '@stdlib/array-filled-by' );
var naryFunction = require( '@stdlib/utils-nary-function' );

function fill( i ) {
    return i;
}

function sum() {
    var s;
    var i;

    s = 0;
    for ( i = 0; i < arguments.length; i++ ) {
        s += arguments[ i ];
    }
    return s;
}

// Create a data array:
var x = filledarrayBy( 10, 'float64', fill );

// Compute cumulative sums...
var f;
var i;
for ( i = 0; i <= x.length; i++ ) {
    f = naryFunction( sum, i );
    console.log( 'sum_%d = %d', i, f.apply( null, x ) );
}
```

</section>

<!-- /.examples -->

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<section class="references">

</section>

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<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/utils-mask-arguments`][@stdlib/utils/mask-arguments]</span><span class="delimiter">: </span><span class="description">create a function that invokes a provided function according to an argument mask.</span>
-   <span class="package-name">[`@stdlib/utils-pick-arguments`][@stdlib/utils/pick-arguments]</span><span class="delimiter">: </span><span class="description">create a function that invokes a provided function with specified arguments.</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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[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-nary-function/tree/deno
[deno-readme]: https://github.com/stdlib-js/utils-nary-function/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/utils-nary-function/tree/umd
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[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/utils-nary-function/main/LICENSE

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[@stdlib/utils/mask-arguments]: https://www.npmjs.com/package/@stdlib/utils-mask-arguments

[@stdlib/utils/pick-arguments]: https://www.npmjs.com/package/@stdlib/utils-pick-arguments

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</section>

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