# Iterator Symbol
> Iterator [symbol][mdn-symbol] which specifies the default iterator for an object.
## Usage
```javascript
var IteratorSymbol = require( '@stdlib/symbol/iterator' );
```
#### IteratorSymbol
Iterator [`symbol`][mdn-symbol] which specifies the default iterator for an object.
```javascript
var s = typeof IteratorSymbol;
// e.g., returns 'symbol'
```
## Notes
- The [symbol][mdn-symbol] is only supported in environments which support [symbols][mdn-symbol]. In non-supporting environments, the value is `null`.
## Examples
```javascript
var IteratorSymbol = require( '@stdlib/symbol/iterator' );
var obj;
var v;
function iterator() {
var iter;
var i;
i = -1;
iter = {};
iter.next = next;
iter.return = done;
if ( IteratorSymbol ) {
// Allow the iterator to work with `for...of`:
iter[ IteratorSymbol ] = iterator;
}
return iter;
function next() {
i += 1;
return {
'value': i,
'done': false
};
}
function done( value ) {
if ( arguments.length === 0 ) {
return {
'done': true
};
}
return {
'value': value,
'done': true
};
}
}
obj = iterator();
while ( v === void 0 || ( v.value < 10 && v.done === false ) ) {
v = obj.next();
console.log( v.value );
}
```
[mdn-symbol]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol