# Async Iterator Symbol
> Async iterator [symbol][mdn-symbol] which specifies the default async iterator for an object.
## Usage
```javascript
var AsyncIteratorSymbol = require( '@stdlib/symbol/async-iterator' );
```
#### AsyncIteratorSymbol
Async iterator [`symbol`][mdn-symbol] which specifies the default async iterator for an object.
```javascript
var s = typeof AsyncIteratorSymbol;
// e.g., returns 'symbol'
```
## Notes
- The [symbol][mdn-symbol] is only supported in environments which support [symbols][mdn-symbol] and async iterators. In non-supporting environments, the value is `null`.
## Examples
```javascript
var AsyncIteratorSymbol = require( '@stdlib/symbol/async-iterator' );
if ( AsyncIteratorSymbol === null ) {
console.log( 'Environment does not support Symbol.asyncIterator.' );
} else {
console.log( 'Environment does support Symbol.asyncIterator.' );
}
```
[mdn-symbol]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol