where.md

This is RxJS v 4. Find the latest version here

Rx.Observable.prototype.filter(predicate, [thisArg])

Rx.Observable.prototype.where(predicate, [thisArg])

Ⓢ

Filters the elements of an observable sequence based on a predicate.

Arguments

1. predicate (Function): A function to test each source element for a condition. The callback is called with the following information:
   1. the value of the element
   2. the index of the element
   3. the Observable object being subscribed
2. [thisArg] (Any): Object to use as this when executing the predicate.

Returns

(Observable): An observable sequence that contains elements from the input sequence that satisfy the condition.

Example

var source = Rx.Observable.range(0, 5)
  .filter(function (x, idx, obs) {
    return x % 2 === 0;
  });

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

// => Next: 0
// => Next: 2
// => Next: 4
// => Completed

Location

File:

• /src/core/perf/operators/filter.js

Dist:

• rx.all.js
• rx.all.compat.js
• rx.js
• rx.compat.js
• rx.lite.js
• rx.lite.compat.js

Prerequisites:

• None

NPM Packages:

• rx

NuGet Packages:

• RxJS-All
• RxJS-Main
• RxJS-Lite

Unit Tests:

• /tests/observable/where.js