Angular2 Observable Filter

Question

I'd like to filter an observable, but am getting unexpected results.

I am using the following import statements:

import {Observable} from 'rxjs/Observable';
import 'rxjs/add/observable/of';

This example returns nothing:

Observable.of([0, 1, 2, 3, 4, 5])
.filter((x: any) => x % 2 === 0)
.subscribe(data => console.log(data));

This example returns the entire result set [0,1,2,3,4,5]:

Observable.of([0, 1, 2, 3, 4, 5])
.filter((x: number[], idx) => x[idx] % 2 === 0)
.subscribe(data => console.log(data));

Does anyone see syntax errors and/or something I am missing? Thank you!

Yury Tarabanko · Accepted Answer · 2016-07-15 19:52:42Z

2

You need to use from if you want to pass values as iterable (array in current case)

import 'rxjs/add/observable/from';

Observable.from([0, 1, 2, 3, 4, 5])
.filter((x: any) => x % 2 === 0)
.subscribe(data => console.log(data));

Or if you want stick with of pass values as arguments

Observable.of(0, 1, 2, 3, 4, 5)
.filter((x: any) => x % 2 === 0)
.subscribe(data => console.log(data));

answered Jul 15, 2016 at 19:52

Yury Tarabanko

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