# hconcat
> Concatenate a list of [ndarrays][@stdlib/ndarray/ctor] along the last dimension.
## Usage
```javascript
var hconcat = require( '@stdlib/ndarray/hconcat' );
```
#### hconcat( arrays )
Concatenates a list of [ndarrays][@stdlib/ndarray/ctor] along the last dimension.
```javascript
var array = require( '@stdlib/ndarray/array' );
var x = array( [ [ 1.0, 2.0 ], [ 3.0, 4.0 ] ] );
// returns [ [ 1.0, 2.0 ], [ 3.0, 4.0 ] ]
var y = array( [ [ 5.0, 6.0, 7.0 ], [ 8.0, 9.0, 10.0 ] ] );
// returns [ [ 5.0, 6.0, 7.0 ], [ 8.0, 9.0, 10.0 ] ]
var out = hconcat( [ x, y ] );
// returns [ [ 1.0, 2.0, 5.0, 6.0, 7.0 ], [ 3.0, 4.0, 8.0, 9.0, 10.0 ] ]
```
The function accepts the following arguments:
- **arrays**: a list of input [ndarrays][@stdlib/ndarray/ctor]. The data type of the output [ndarray][@stdlib/ndarray/ctor] is determined by applying [type promotion rules][@stdlib/ndarray/promotion-rules] to the list of input [ndarrays][@stdlib/ndarray/ctor]. If provided [ndarrays][@stdlib/ndarray/ctor] having different [memory layouts][@stdlib/ndarray/orders], the output [ndarray][@stdlib/ndarray/ctor] has the [default order][@stdlib/ndarray/defaults].
#### hconcat.assign( arrays, out )
Concatenates a list of [ndarrays][@stdlib/ndarray/ctor] along the last dimension and assigns results to a provided output [ndarray][@stdlib/ndarray/ctor].
```javascript
var array = require( '@stdlib/ndarray/array' );
var zeros = require( '@stdlib/ndarray/zeros' );
var x = array( [ [ 1.0, 2.0 ], [ 3.0, 4.0 ] ] );
// returns [ [ 1.0, 2.0 ], [ 3.0, 4.0 ] ]
var y = array( [ [ 5.0, 6.0, 7.0 ], [ 8.0, 9.0, 10.0 ] ] );
// returns [ [ 5.0, 6.0, 7.0 ], [ 8.0, 9.0, 10.0 ] ]
var z = zeros( [ 2, 5 ] );
// returns [ [ 0.0, 0.0, 0.0, 0.0, 0.0 ], [ 0.0, 0.0, 0.0, 0.0, 0.0 ] ]
var out = hconcat.assign( [ x, y ], z );
// returns [ [ 1.0, 2.0, 5.0, 6.0, 7.0 ], [ 3.0, 4.0, 8.0, 9.0, 10.0 ] ]
var bool = ( out === z );
// returns true
```
The function accepts the following arguments:
- **arrays**: a list of input [ndarrays][@stdlib/ndarray/ctor]. Must [promote][@stdlib/ndarray/promotion-rules] to a [data type][@stdlib/ndarray/dtypes] which can be (mostly) [safely cast][@stdlib/ndarray/mostly-safe-casts] to the [data type][@stdlib/ndarray/dtypes] of the output [ndarray][@stdlib/ndarray/ctor].
- **out**: output [ndarray][@stdlib/ndarray/ctor].
## Examples
```javascript
var discreteUniform = require( '@stdlib/random/discrete-uniform' );
var ndarray2array = require( '@stdlib/ndarray/to-array' );
var hconcat = require( '@stdlib/ndarray/hconcat' );
var x = discreteUniform( [ 2, 2 ], 0, 10, {
'dtype': 'generic'
});
console.log( ndarray2array( x ) );
var y = discreteUniform( [ 2, 3 ], 0, 10, {
'dtype': 'generic'
});
console.log( ndarray2array( y ) );
var out = hconcat( [ x, y ] );
console.log( ndarray2array( out ) );
```
[@stdlib/ndarray/ctor]: https://github.com/stdlib-js/ndarray/tree/main/ctor
[@stdlib/ndarray/dtypes]: https://github.com/stdlib-js/ndarray/tree/main/dtypes
[@stdlib/ndarray/orders]: https://github.com/stdlib-js/ndarray/tree/main/orders
[@stdlib/ndarray/defaults]: https://github.com/stdlib-js/ndarray/tree/main/defaults
[@stdlib/ndarray/promotion-rules]: https://github.com/stdlib-js/ndarray/tree/main/promotion-rules
[@stdlib/ndarray/mostly-safe-casts]: https://github.com/stdlib-js/ndarray/tree/main/mostly-safe-casts