Reactive-Extensions/RxJS

# This is RxJS v 4. [Find the latest version here](https://github.com/reactivex/rxjs)
### <a id="rxobservableprototypeambrightsource"></a>`Rx.Observable.prototype.amb(rightSource)`
<a href="#rxobservableprototypeambrightsource">#</a> [&#x24C8;](https://github.com/Reactive-Extensions/RxJS/blob/master/src/core/linq/observable/ambproto.js "View in source")
 
Propagates the observable sequence that reacts first.
 
#### Arguments
1. `rightSource` *(`Observable`)*: Second observable sequence.
 
#### Returns
*(`Observable`)*: An observable sequence that surfaces either of the given sequences, whichever reacted first.
 
#### Example
```js
var first = Rx.Observable.timer(300).map(function () { return 'first'; });
var second = Rx.Observable.timer(500).map(function () { return 'second'; });
 
var source = first.amb(second);
 
var subscription = source.subscribe(
    function (x) {
        console.log('Next: ' + x);
    },
    function (err) {
        console.log('Error: ' + err);
    },
    function () {
        console.log('Completed');
    });
 
// => Next: first
// => Completed
```
 
### Location
 
File:
- [/src/core/linq/observable/ambproto.js](https://github.com/Reactive-Extensions/RxJS/blob/master/src/core/linq/observable/ambproto.js)
 
Dist:
- [`rx.js`](https://github.com/Reactive-Extensions/RxJS/blob/master/dist/rx.js)
- [`rx.compat.js`](https://github.com/Reactive-Extensions/RxJS/blob/master/dist/rx.compat.js)
- [`rx.all.js`](https://github.com/Reactive-Extensions/RxJS/blob/master/dist/rx.all.js)
- [`rx.all.compat.js`](https://github.com/Reactive-Extensions/RxJS/blob/master/dist/rx.all.compat.js)
- [`rx.lite.extras.js`](https://github.com/Reactive-Extensions/RxJS/blob/master/dist/rx.lite.extras.js)
 
Prerequisites:
- None
 
NPM Packages:
- [`rx`](https://www.npmjs.org/package/rx)
 
NuGet Packages:
- [`RxJS-All`](http://www.nuget.org/packages/RxJS-All/)
- [`RxJS-Main`](http://www.nuget.org/packages/RxJS-Main/)
- [`RxJS-Lite`](http://www.nuget.org/packages/RxJS-Lite/)
 
Unit Tests:
- [/tests/observable/amb.js](https://github.com/Reactive-Extensions/RxJS/blob/master/tests/observable/amb.js)