> For the complete documentation index, see [llms.txt](https://soufatn.gitbook.io/rxjs-book/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://soufatn.gitbook.io/rxjs-book/summary/observable/observable_instance_methods/includes.md).

# includes

Determines whether an observable sequence includes a specified element with an optional from index.

## Arguments

1. `searchElement` *(`Any`)*: The value to locate in the source sequence.
2. `[fromIndex]` *(`Number`)*: The index to start the search.  If not specified, defaults to 0.

## Returns

*(`Observable`)*: An observable sequence containing a single element determining whether the source sequence includes an element that has the specified value with an optional from index.

## Example

```javascript
/* Without an index */
var source = Rx.Observable.of(42)
  .includes(42);

var subscription = source.subscribe(
  function (x) {
    console.log('Next: %s', x);
  },
  function (err) {
    console.log('Error: %s', err);
  },
  function () {
      console.log('Completed');
  });

// => Next: true
// => Completed

/* With an index */
var source = Rx.Observable.of(1,2,3)
  .includes(2, 1);

var subscription = source.subscribe(
  function (x) {
    console.log('Next: %s', x);
  },
  function (err) {
    console.log('Error: %s', err);
  },
  function () {
    console.log('Completed');
  });

// => Next: true
// => Completed
```