npm package: @stdlib/array-base-accessor-getter
Description: Return an accessor function for retrieving an element from an array-like object supporting the get/set protocol.
Author: The Stdlib Authors
Latest version: 0.2.3

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# accessorGetter

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> Return an accessor function for retrieving an element from an array-like object supporting the get/set protocol.

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<section class="intro">

</section>

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<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/array-base-accessor-getter
```

</section>

<section class="usage">

## Usage

```javascript
var accessorGetter = require( '@stdlib/array-base-accessor-getter' );
```

#### accessorGetter( dtype )

Returns an accessor function for retrieving an element from an array-like object supporting the get/set protocol.

```javascript
var Complex64Array = require( '@stdlib/array-complex64' );

var arr = new Complex64Array( [ 1, 2, 3, 4 ] );

var get = accessorGetter( 'complex64' );
var v = get( arr, 1 );
// returns <Complex64>[ 3.0, 4.0 ]
```

The returned accessor function accepts the following arguments:

-   **arr**: input array.
-   **idx**: element index.

</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 provided an unsupported [`dtype`][@stdlib/array/dtypes], the function returns a default accessor function for accessing elements from any indexed array-like object supporting the get/set protocol; otherwise, the function returns an accessor function which should **only** be provided an array instance corresponding to `dtype` (e.g., if `dtype` is `'complex64'`, the returned accessor function should only be provided instances of `Complex64Array`).
-   Accessor functions do **not** verify that provided input arrays are array instances corresponding to `dtype`, as doing so would introduce performance overhead. If array instances corresponding to other data types are provided to an accessor function, JavaScript runtimes will consider the function polymorphic, potentially triggering de-optimization. In order to ensure maximum performance, **always** ensure that an accessor function is monomorphic.
-   Accessor functions do **not** perform bounds checking.
-   Accessor functions do **not** verify that provided input arrays actually implement the get/set protocol.
-   An array-like object supporting the get/set protocol is a data structure in which one accesses elements using explicit `get` and `set` methods (e.g., `Complex64Array` and `Complex128Array`).

</section>

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<!-- Package usage examples. -->

<section class="examples">

## Examples

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

```javascript
var Complex128Array = require( '@stdlib/array-complex128' );
var Complex64Array = require( '@stdlib/array-complex64' );
var zeroTo = require( '@stdlib/array-base-zero-to' );
var dtype = require( '@stdlib/array-dtype' );
var accessorGetter = require( '@stdlib/array-base-accessor-getter' );

var arr = new Complex128Array( zeroTo( 10 ) );
var v = accessorGetter( dtype( arr ) )( arr, 2 );
// returns <Complex128>[ 4.0, 5.0 ]

console.log( v.toString() );
// => '4 + 5i'

arr = new Complex64Array( zeroTo( 10 ) );
v = accessorGetter( dtype( arr ) )( arr, 4 );
// returns <Complex64>[ 8.0, 9.0 ]

console.log( v.toString() );
// => '8 + 9i'
```

</section>

<!-- /.examples -->

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

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