npm package: @stdlib/array-base-for-each
Description: Invoke a callback function once for each array element.
Author: The Stdlib Authors
Latest version: 0.1.1

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# forEach

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

> Invoke a callback function once for each array element.

<!-- 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-base-for-each
```

</section>

<section class="usage">

## Usage

```javascript
var forEach = require( '@stdlib/array-base-for-each' );
```

#### forEach( x, fcn\[, thisArg] )

Invokes a callback function once for each array element.

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

var x = [ 1, 2, 3, 4 ];

forEach( x, naryFunction( log, 1 ) );
```

The function accepts the following arguments:

-   **x**: input array.
-   **fcn**: callback to apply.
-   **thisArg**: callback execution context _(optional)_.

To set the callback function execution context, provide a `thisArg`.

<!-- eslint-disable no-invalid-this -->

```javascript
function accumulate( z ) {
    this.sum += z;
}

var x = [ 1, 2, 3, 4 ];

var ctx = {
    'sum': 0
};

forEach( x, accumulate, ctx );
var sum = ctx.sum;
// returns 10
```

The callback function is provided the following arguments:

-   **value**: current array element.
-   **index**: current array element index.
-   **arr**: the input array.

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

    ```text
    x.forEach( fcn, thisArg )
    ```

-   The function support array-like objects having getter and setter accessors for array element access (e.g., [`@stdlib/array-base/accessor`][@stdlib/array/base/accessor]).

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

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

```javascript
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var naryFunction = require( '@stdlib/utils-nary-function' );
var log = require( '@stdlib/console-log' );
var forEach = require( '@stdlib/array-base-for-each' );

var x = discreteUniform( 10, 0, 10, {
    'dtype': 'float64'
});

forEach( x, naryFunction( log, 1 ) );
```

</section>

<!-- /.examples -->

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<section class="related">

</section>

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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>

<!-- /.stdlib -->

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[npm-image]: http://img.shields.io/npm/v/@stdlib/array-base-for-each.svg
[npm-url]: https://npmjs.org/package/@stdlib/array-base-for-each

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

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/array-base-for-each/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/array-base-for-each?branch=main

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[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-base-for-each/tree/deno
[deno-readme]: https://github.com/stdlib-js/array-base-for-each/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/array-base-for-each/tree/umd
[umd-readme]: https://github.com/stdlib-js/array-base-for-each/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/array-base-for-each/tree/esm
[esm-readme]: https://github.com/stdlib-js/array-base-for-each/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/array-base-for-each/blob/main/branches.md

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

[@stdlib/array/base/accessor]: https://www.npmjs.com/package/@stdlib/array-base-accessor

</section>

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