npm package: @stdlib/slice-base-length
Description: Compute the number of elements in a normalized slice.
Author: The Stdlib Authors
Latest version: 0.2.3

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# sliceLength

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> Compute the number of elements in a [normalized slice][@stdlib/slice/base/normalize-slice].

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<section class="intro">

</section>

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<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/slice-base-length
```

</section>

<section class="usage">

## Usage

```javascript
var sliceLength = require( '@stdlib/slice-base-length' );
```

<a name="main"></a>

#### sliceLength( slice )

Returns the number of elements in a [normalized slice][@stdlib/slice/base/normalize-slice].

```javascript
var Slice = require( '@stdlib/slice-ctor' );
var normalizeSlice = require( '@stdlib/slice-base-normalize-slice' );

var s = normalizeSlice( new Slice( -3, null, -1 ), 10, false );
// returns <Slice>

var len = sliceLength( s );
// returns 8
```

</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" -->

```javascript
var Slice = require( '@stdlib/slice-ctor' );
var normalizeSlice = require( '@stdlib/slice-base-normalize-slice' );
var incrspace = require( '@stdlib/array-base-incrspace' );
var sliceLength = require( '@stdlib/slice-base-length' );

var s1 = new Slice( 2, null, -1 );
var s2 = normalizeSlice( s1, 10, false );
var v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 2, 1, 0 ]'

s1 = new Slice( null, null, -3 );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 9, 6, 3, 0 ]'

s1 = new Slice( null, 8, 3 );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 0, 3, 6 ]'

s1 = new Slice( null, 8, null );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 0, 1, 2, 3, 4, 5, 6, 7 ]'

s1 = new Slice( -4, null, -2 );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 6, 4, 2, 0 ]'

s1 = new Slice( null, 8, 3 );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 0, 3, 6 ]'

s1 = new Slice( 8, 2, -2 );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 8, 6, 4 ]'

s1 = new Slice( 3, 8, 2 );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 3, 5, 7 ]'
```

</section>

<!-- /.examples -->

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</section>

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* * *

## See Also

-   <span class="package-name">[`@stdlib/slice-base/nonreduced-dimensions`][@stdlib/slice/base/nonreduced-dimensions]</span><span class="delimiter">: </span><span class="description">return a list of non-reduced dimensions in an un-normalized multi-slice.</span>
-   <span class="package-name">[`@stdlib/slice-base/reduced-dimensions`][@stdlib/slice/base/reduced-dimensions]</span><span class="delimiter">: </span><span class="description">return a list of reduced dimensions in an un-normalized multi-slice.</span>
-   <span class="package-name">[`@stdlib/slice-base/shape`][@stdlib/slice/base/shape]</span><span class="delimiter">: </span><span class="description">compute the shape of a normalized multi-slice.</span>

</section>

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* * *

## 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].

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## License

See [LICENSE][stdlib-license].


## Copyright

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

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[@stdlib/slice/base/normalize-slice]: https://www.npmjs.com/package/@stdlib/slice-base-normalize-slice

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[@stdlib/slice/base/shape]: https://www.npmjs.com/package/@stdlib/slice-base-shape

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