# share

#### signature: `share(): Observable`

## Share source among multiple subscribers.

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💡 share is like [multicast](https://www.learnrxjs.io/learn-rxjs/operators/multicasting/multicast) with a Subject and refCount!

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### Examples

**Example 1: Multiple subscribers sharing source**

( [StackBlitz](https://stackblitz.com/edit/typescript-dlaa1p?file=index.ts\&devtoolsheight=100) | [jsBin](http://jsbin.com/jobiyomari/1/edit?js,console) | [jsFiddle](https://jsfiddle.net/btroncone/Lmesxxaq/) )

```js
// RxJS v6+
import { timer } from 'rxjs';
import { tap, mapTo, share } from 'rxjs/operators';

//emit value in 1s
const source = timer(1000);
//log side effect, emit result
const example = source.pipe(
  tap(() => console.log('***SIDE EFFECT***')),
  mapTo('***RESULT***')
);

/*
  ***NOT SHARED, SIDE EFFECT WILL BE EXECUTED TWICE***
  output:
  "***SIDE EFFECT***"
  "***RESULT***"
  "***SIDE EFFECT***"
  "***RESULT***"
*/
const subscribe = example.subscribe(val => console.log(val));
const subscribeTwo = example.subscribe(val => console.log(val));

//share observable among subscribers
const sharedExample = example.pipe(share());
/*
  ***SHARED, SIDE EFFECT EXECUTED ONCE***
  output:
  "***SIDE EFFECT***"
  "***RESULT***"
  "***RESULT***"
*/
const subscribeThree = sharedExample.subscribe(val => console.log(val));
const subscribeFour = sharedExample.subscribe(val => console.log(val));
```

### Related Recipes

* [Progress Bar](https://www.learnrxjs.io/learn-rxjs/recipes/progressbar)
* [Game Loop](https://www.learnrxjs.io/learn-rxjs/recipes/gameloop)
* [Save Indicator](https://www.learnrxjs.io/learn-rxjs/recipes/save-indicator)

### Additional Resources

* [share](https://rxjs.dev/api/operators/share) 📰 - Official docs
* [Sharing streams with share](https://egghead.io/lessons/rxjs-sharing-streams-with-share?course=step-by-step-async-javascript-with-rxjs) 🎥 💵 - John Linquist

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> 📁 Source Code: <https://github.com/ReactiveX/rxjs/blob/master/packages/rxjs/src/internal/operators/share.ts>