Understand Reactive Programming using RxJS

How does the reduce function know that you've reached the end of the event stream?

Hi Brendan. A stream can emit 3 types of events: normal data to the next callback, errors to the error callback, and end of stream with the complete callback. This is how the reduce operator can conclude with one value: as soon as the source completes, it outputs the reduced value.

Cool thx

Observable.interval(400).take(9).map(...) is not explained. Why? Never mind the man behind the curtain?

4:21 - it should be 42, not 33.

Please get a microphone pop filter

This is such a great intro to the concept.

i am unable to understand below syntax - var source = Rx.Observable.interval(400).take(9) .map(i => ['1', '1', 'foo', '2', '3', '5', 'bar', '8', '13'][i]); The array inside map method, which one is our calling array.

André is accessing the array through the index. You can read more about it here. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array#access_an_array_item_by_its_index