# nans
> Create an array filled with NaNs and having a specified length.
## Usage
```javascript
var nans = require( '@stdlib/array/nans' );
```
#### nans( length\[, dtype] )
Creates an array filled with NaNs and having a specified length.
```javascript
var arr = nans( 2 );
// returns [ NaN, NaN ]
```
The function recognizes the following data types:
- `float64`: double-precision floating-point numbers (IEEE 754)
- `float32`: single-precision floating-point numbers (IEEE 754)
- `complex128`: double-precision complex floating-point numbers
- `complex64`: single-precision complex floating-point numbers
- `generic`: generic JavaScript values
By default, the output array data type is `float64` (i.e., a [typed array][mdn-typed-array]). To specify an alternative data type, provide a `dtype` argument.
```javascript
var arr = nans( 2, 'float32' );
// returns [ NaN, NaN ]
```
## Notes
- For complex number arrays, each element of the returned array has a real component equal to `NaN` and an imaginary component equal to `NaN`.
## Examples
```javascript
var dtypes = require( '@stdlib/array/typed-float-dtypes' );
var nans = require( '@stdlib/array/nans' );
// Get a list of array data types:
var dt = dtypes();
// Generate filled arrays...
var arr;
var i;
for ( i = 0; i < dt.length; i++ ) {
arr = nans( 4, dt[ i ] );
console.log( arr );
}
```
[mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
[@stdlib/array/full]: https://github.com/stdlib-js/array/tree/main/full
[@stdlib/array/nans-like]: https://github.com/stdlib-js/array/tree/main/nans-like
[@stdlib/array/ones]: https://github.com/stdlib-js/array/tree/main/ones
[@stdlib/array/zeros]: https://github.com/stdlib-js/array/tree/main/zeros