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# emptyLike

> Create an uninitialized [ndarray][@stdlib/ndarray/ctor] having the same shape and [data type][@stdlib/ndarray/dtypes] as a provided ndarray.

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<section class="intro">

</section>

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<section class="usage">

## Usage

```javascript
var emptyLike = require( '@stdlib/ndarray/empty-like' );
```

#### emptyLike( x\[, options] )

Creates an uninitialized [ndarray][@stdlib/ndarray/ctor] having the same shape and [data type][@stdlib/ndarray/dtypes] as a provided ndarray.

```javascript
var getShape = require( '@stdlib/ndarray/shape' );
var getDType = require( '@stdlib/ndarray/dtype' );
var zeros = require( '@stdlib/ndarray/zeros' );

var x = zeros( [ 2, 2 ] );
// returns <ndarray>[ [ 0.0, 0.0 ], [ 0.0, 0.0 ] ]

var y = emptyLike( x );
// returns <ndarray>

var sh = getShape( y );
// returns [ 2, 2 ]

var dt = String( getDType( y ) );
// returns 'float64'
```

The function supports the following `options`:

-   **dtype**: output [ndarray][@stdlib/ndarray/ctor] [data type][@stdlib/ndarray/dtypes]. Overrides the input ndarray's inferred [data type][@stdlib/ndarray/dtypes].
-   **shape**: output [ndarray][@stdlib/ndarray/ctor] shape. Overrides the input ndarray's inferred shape.
-   **order**: specifies whether the output [ndarray][@stdlib/ndarray/ctor] should be `'row-major'` (C-style) or `'column-major'` (Fortran-style). Overrides the input ndarray's inferred order.
-   **mode**: specifies how to handle indices which exceed array dimensions (see [ndarray][@stdlib/ndarray/ctor]). Default: `'throw'`.
-   **submode**: a mode array which specifies for each dimension how to handle subscripts which exceed array dimensions  (see [ndarray][@stdlib/ndarray/ctor]). If provided fewer modes than dimensions, the constructor recycles modes using modulo arithmetic. Default: `[ options.mode ]`.

To override either the `dtype`, `shape`, or `order`, specify the corresponding option. For example, to override the inferred [data type][@stdlib/ndarray/dtypes],

```javascript
var getShape = require( '@stdlib/ndarray/shape' );
var getDType = require( '@stdlib/ndarray/dtype' );
var zeros = require( '@stdlib/ndarray/zeros' );

var x = zeros( [ 2, 2 ] );
// returns <ndarray>[ [ 0.0, 0.0 ], [ 0.0, 0.0 ] ]

var dt = String( getDType( x ) );
// returns 'float64'

var y = emptyLike( x, {
    'dtype': 'int32'
});
// returns <ndarray>

var sh = getShape( y );
// returns [ 2, 2 ]

dt = String( getDType( y ) );
// returns 'int32'
```

</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 the resolved output data type is `'generic'`, the function always returns a zero-filled array.
-   For returned [ndarrays][@stdlib/ndarray/ctor] whose underlying memory is **not** initialized, memory contents are unknown and may contain **sensitive** data.

</section>

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<section class="examples">

## Examples

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

```javascript
var dtypes = require( '@stdlib/ndarray/dtypes' );
var empty = require( '@stdlib/ndarray/empty' );
var ndarray2array = require( '@stdlib/ndarray/to-array' );
var emptyLike = require( '@stdlib/ndarray/empty-like' );

// Get a list of data types:
var dt = dtypes( 'integer_and_generic' );

// Generate uninitialized arrays...
var x;
var y;
var i;
for ( i = 0; i < dt.length; i++ ) {
    x = empty( [ 2, 2 ], {
        'dtype': dt[ i ]
    });
    y = emptyLike( x );
    console.log( ndarray2array( y ) );
}
```

</section>

<!-- /.examples -->

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</section>

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* * *

## See Also

-   <span class="package-name">[`@stdlib/ndarray/empty`][@stdlib/ndarray/empty]</span><span class="delimiter">: </span><span class="description">create an uninitialized ndarray having a specified shape and data type.</span>
-   <span class="package-name">[`@stdlib/ndarray/zeros-like`][@stdlib/ndarray/zeros-like]</span><span class="delimiter">: </span><span class="description">create a zero-filled ndarray having the same shape and data type as a provided ndarray.</span>

</section>

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<section class="links">

[@stdlib/ndarray/ctor]: https://github.com/stdlib-js/ndarray/tree/main/ctor

[@stdlib/ndarray/dtypes]: https://github.com/stdlib-js/ndarray/tree/main/dtypes

<!-- <related-links> -->

[@stdlib/ndarray/empty]: https://github.com/stdlib-js/ndarray/tree/main/empty

[@stdlib/ndarray/zeros-like]: https://github.com/stdlib-js/ndarray/tree/main/zeros-like

<!-- </related-links> -->

</section>

<!-- /.links -->
