npm package: @stdlib/iter-concat
Description: Create an iterator which iterates over the values of two or more iterators.
Author: The Stdlib Authors
Latest version: 0.2.3

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# iterConcat

[![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 [iterator][mdn-iterator-protocol] which iterates over the values of two or more [iterators][mdn-iterator-protocol].

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<section class="intro">

</section>

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<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/iter-concat
```

</section>

<section class="usage">

## Usage

```javascript
var iterConcat = require( '@stdlib/iter-concat' );
```

#### iterConcat( iter0, ...iterator )

Returns an [iterator][mdn-iterator-protocol] which iterates over the values of two or more [iterators][mdn-iterator-protocol].

```javascript
var array2iterator = require( '@stdlib/array-to-iterator' );

var it1 = array2iterator( [ 1, 2 ] );
var it2 = array2iterator( [ 3, 4 ] );

var it = iterConcat( it1, it2 );
// returns <Object>

var v = it.next().value;
// returns 1

v = it.next().value;
// returns 2

v = it.next().value;
// returns 3

v = it.next().value;
// returns 4

var bool = it.next().done;
// returns true
```

The returned [iterator][mdn-iterator-protocol] protocol-compliant object has the following properties:

-   **next**: function which returns an [iterator][mdn-iterator-protocol] protocol-compliant object containing the next iterated value (if one exists) assigned to a `value` property and a `done` property having a `boolean` value indicating whether the [iterator][mdn-iterator-protocol] is finished.
-   **return**: function which closes an [iterator][mdn-iterator-protocol] and returns a single (optional) argument in an [iterator][mdn-iterator-protocol] protocol-compliant object.

</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 an environment supports `Symbol.iterator` **and** provided [iterators][mdn-iterator-protocol] are iterable, the returned [iterator][mdn-iterator-protocol] is iterable.

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

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

```javascript
var randu = require( '@stdlib/random-iter-randu' );
var randn = require( '@stdlib/random-iter-randn' );
var iterConcat = require( '@stdlib/iter-concat' );

// Create a seeded iterator for generating uniformly distributed pseudorandom numbers:
var runif = randu({
    'seed': 1234,
    'iter': 10
});

// Create a seeded iterator for generating normally distributed pseudorandom numbers:
var rnorm = randn({
    'seed': 1234,
    'iter': 10
});

// Create an iterator which concatenates iterators:
var it = iterConcat( runif, rnorm );

// Perform manual iteration...
var v;
while ( true ) {
    v = it.next();
    if ( v.done ) {
        break;
    }
    console.log( v.value );
}
```

</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>

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<section class="links">

[npm-image]: http://img.shields.io/npm/v/@stdlib/iter-concat.svg
[npm-url]: https://npmjs.org/package/@stdlib/iter-concat

[test-image]: https://github.com/stdlib-js/iter-concat/actions/workflows/test.yml/badge.svg?branch=v0.2.3
[test-url]: https://github.com/stdlib-js/iter-concat/actions/workflows/test.yml?query=branch:v0.2.3

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[coverage-url]: https://codecov.io/github/stdlib-js/iter-concat?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/iter-concat/tree/deno
[deno-readme]: https://github.com/stdlib-js/iter-concat/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/iter-concat/tree/umd
[umd-readme]: https://github.com/stdlib-js/iter-concat/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/iter-concat/tree/esm
[esm-readme]: https://github.com/stdlib-js/iter-concat/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/iter-concat/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/iter-concat/main/LICENSE

[mdn-iterator-protocol]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#The_iterator_protocol

</section>

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