@stdlib/iter/nth/README.md

Standard iterator utilities.

<!--

@license Apache-2.0

Copyright (c) 2018 The Stdlib Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

-->

# iterNth

> Return the nth [iterated][mdn-iterator-protocol] value.

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- Package usage documentation. -->

<section class="usage">

## Usage

```javascript
var iterNth = require( '@stdlib/iter/nth' );
```

#### iterNth( iterator, n )

Returns the nth [iterated][mdn-iterator-protocol] value.

```javascript
var array2iterator = require( '@stdlib/array/to-iterator' );

var arr = array2iterator( [ 0, 0, 1, 0, 0 ] );

var v = iterNth( arr, 3 );
// returns 1
```

If `n` exceeds the total number of [iterated][mdn-iterator-protocol] values, the function returns `undefined`.

```javascript
var array2iterator = require( '@stdlib/array/to-iterator' );

var arr = array2iterator( [ 0, 0, 1, 0, 0 ] );

var v = iterNth( arr, 10 );
// returns undefined
```

</section>

<!-- /.usage -->

<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

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

```javascript
var randu = require( '@stdlib/random/iter/randu' );
var iterMap = require( '@stdlib/iter/map' );
var iterNth = require( '@stdlib/iter/nth' );

function threshold( r ) {
    return ( r > 0.95 );
}

// Create an iterator which generates uniformly distributed pseudorandom numbers:
var opts = {
    'iter': 100
};
var riter = randu( opts );

// Create an iterator which applies a threshold to generated numbers:
var miter = iterMap( riter, threshold );

// Return the 50th threshold result:
var bool = iterNth( miter, 50 );
// returns <boolean>

console.log( bool );
```

</section>

<!-- /.examples -->

<!-- Section to include cited references. If references are included, add a horizontal rule *before* the section. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="references">

</section>

<!-- /.references -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/iter/first`][@stdlib/iter/first]</span><span class="delimiter">: </span><span class="description">return the first iterated value.</span>
-   <span class="package-name">[`@stdlib/iter/last`][@stdlib/iter/last]</span><span class="delimiter">: </span><span class="description">consume an entire iterator and return the last iterated value.</span>

</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

[mdn-iterator-protocol]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#The_iterator_protocol

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

[@stdlib/iter/first]: https://github.com/stdlib-js/iter/tree/main/first

[@stdlib/iter/last]: https://github.com/stdlib-js/iter/tree/main/last

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

</section>

<!-- /.links -->