# iterLength
> Return an [iterator][mdn-iterator-protocol]'s length.
## Usage
```javascript
var iterLength = require( '@stdlib/iter/length' );
```
#### iterLength( iterator )
Consumes an entire [iterator][mdn-iterator-protocol] and returns the number of [iterated][mdn-iterator-protocol] values (i.e., the [iterator][mdn-iterator-protocol] length).
```javascript
var array2iterator = require( '@stdlib/array/to-iterator' );
var arr = array2iterator( [ 0, 0, 0, 0, 1 ] );
var len = iterLength( arr );
// returns 5
```
If a provided [`iterator`][mdn-iterator-protocol] does not return any [iterated][mdn-iterator-protocol] values, the function returns `0`.
```javascript
var iterEmpty = require( '@stdlib/iter/empty' );
var len = iterLength( iterEmpty() );
// returns 0
```
## Examples
```javascript
var randu = require( '@stdlib/random/iter/randu' );
var iterLength = require( '@stdlib/iter/length' );
// Create an iterator which generates uniformly distributed pseudorandom numbers:
var opts = {
'iter': 100
};
var iter = randu( opts );
// Determine the iterator length:
var len = iterLength( iter );
// returns 100
```
[mdn-iterator-protocol]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#The_iterator_protocol
[@stdlib/iter/counter]: https://github.com/stdlib-js/iter/tree/main/counter