npm package: @stdlib/ndarray-numel
Description: Return the number of elements in an ndarray.
Author: The Stdlib Authors
Latest version: 0.2.3

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<details>
  <summary>
    About stdlib...
  </summary>
  <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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# numel

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

> Return the number of elements in an [ndarray][@stdlib/ndarray/ctor].

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<section class="intro">

</section>

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<section class="installation">

## Installation

```bash
npm install @stdlib/ndarray-numel
```

</section>

<section class="usage">

## Usage

```javascript
var numel = require( '@stdlib/ndarray-numel' );
```

#### numel( x )

Returns the number of elements in an [ndarray][@stdlib/ndarray/ctor].

```javascript
var zeros = require( '@stdlib/ndarray-zeros' );

var x = zeros( [ 3, 2, 3 ] );
// returns <ndarray>

var n = numel( x );
// returns 18
```

</section>

<!-- /.usage -->

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<section class="notes">

</section>

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<!-- Package usage examples. -->

<section class="examples">

## Examples

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

<!-- eslint-disable new-cap -->

```javascript
var zeros = require( '@stdlib/ndarray-zeros' );
var slice = require( '@stdlib/ndarray-slice' );
var E = require( '@stdlib/slice-multi' );
var S = require( '@stdlib/slice-ctor' );
var numel = require( '@stdlib/ndarray-numel' );

// Create an array:
var x = zeros( [ 10, 10, 10, 10 ] );
// returns <ndarray>

// Define some slices:
var slices = [
    // :,:,:,:
    E( null, null, null, null ),

    // 5:10,:,2:4,::-1
    E( S( 5, 10 ), null, S( 2, 4 ), S( null, null, -1 ) ),

    // :,:,2,:
    E( null, null, 2, null ),

    // 1,2,3,4
    E( 1, 2, 3, 4 ),

    // :,:,::2,4::2
    E( null, null, S( null, null, 2 ), S( 4, null, 2 ) )
];

// Determine the number of elements in each slice...
var s;
var i;
for ( i = 0; i < slices.length; i++ ) {
    s = slice( x, slices[ i ] );
    console.log( '%s => %d elements', s.shape.join( 'x' ), numel( s ) );
}
```

</section>

<!-- /.examples -->

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</section>

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* * *

## See Also

-   <span class="package-name">[`@stdlib/ndarray-array`][@stdlib/ndarray/array]</span><span class="delimiter">: </span><span class="description">multidimensional arrays.</span>
-   <span class="package-name">[`@stdlib/ndarray-ctor`][@stdlib/ndarray/ctor]</span><span class="delimiter">: </span><span class="description">multidimensional array constructor.</span>
-   <span class="package-name">[`@stdlib/ndarray-numel-dimension`][@stdlib/ndarray/numel-dimension]</span><span class="delimiter">: </span><span class="description">return the size (i.e., number of elements) of a specified dimension for a provided ndarray.</span>

</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

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---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

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[@stdlib/ndarray/ctor]: https://www.npmjs.com/package/@stdlib/ndarray-ctor

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

[@stdlib/ndarray/numel-dimension]: https://www.npmjs.com/package/@stdlib/ndarray-numel-dimension

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