How are Observables Different from Promises? | Beginner RXJS Lessons

What is the Difference Between Subject and Behavior Subject? How are observables different from promises? When should you use which? Why does learning Angular require learning so much more than just learning Angular!?

RXJS beginners, the struggle is real! This video will help you better understand RXJS and how to read RXJS documentation using a simple, illustrated metaphor by which to interpret the differences between Promises and Observables. I also go over a few more concepts that I struggled with when I started, included the role of Observers, and the difference between a Behavior Subject and a Subject.

PART 2:
RXJS Operators Explained with Examples: Switchmap, Map, + More

Real Examples of RXJS in my own projects:

CONTENTS:
0:42 Review
1:17 Three Stories:
1:17 Pull Protocol
1:43 Promises: Push Protocol,
2:32 Observables: Push Protocol
3:41 What’s the difference between a promise and an observable?
4:46 Understand RXJS: How to interpret the documentation
5:08 What is an Observer?
5:42 What is a Subject?
6:12 What is a BehaviorSubject?
6:51 When do you use a Subject and when do you use a BehaviorSubject?
7:04 RXJS Observables in code
8:12 Conclusion

OFFICIAL DOCUMENTATION

MY GEAR
Sony ZV 1

Fifine Condenser Recording Microphone (which was unplugged about halfway through this video: sorry!)

[nickkaragiannis]

Dear lord the value of this video stands above all others...I am literally in shock on how many paid courses fail to deliver information compared to this gem. Amazing work Ben!

[skarntotal]

This video is pure gold, i've looking a lot for a video like this. Keep doing awesome content!

[jayanthavasarala]

If YouTube ever makes a love button, this video definitely deserves it!

[VamsiKrishna-cgwc]

Absolutely the best and concise video I've ever watched till date.

[ranjandass]

This is the video one should watch before interview to understand the concept better with a full proof example 🤣

[tonyz]

Holy shit, your video helped me understand what an observable is. It confused me for so long. Great stories and explanations! Thank you

[Oda]

Best video on explaining observable. Now finally understand what it is!!

[Themerp]

I loaded like 5 videos on Observables and RxJS and this was the first one that made immediate sense to me. Also I loved the use of metaphors that not only explain observables but also explained synchronous codes and promises very well. I will probably keep those examples in mind if I need to explain this concept to anyone else. I also liked that you used the definitions directly from the documentation to further explain things. Instant subscribe from me, I hope to watch and learn from more of such videos.

[Ruan]

Thank you!
Your descriptive and concise sharing of knowledge in a relatable metaphoric way is so useful and easily comprehendible!
Commendable video!

[hawaijarmayengbam]

That three versions of the story and most notably the Weather/Radio part will form my mental model on Push vs Pull and Promise vs Observable concepts. Thank you and you made my day!

[MichaelSchoelkopf]

Based on my YouTube history I have watched 12 videos about Observables. This one is the best to understand them. Thanks a lot for putting in the effort and use this real life example.

[metorado]

Great explanation man! I've being coding like 5 years long and this clarified my mind about observables splendidly.

[DodaGarcia]

This is so well put together! Love the subtle animation style.

[pedrochatelain]

Best explanation I've seen so far. Thanks a lot Ben!

[neverbenbetter]

Concerning Promises and Observables, I would like to add: Promises are a way to add asynchronous or threading to an app, Observables are a way to extend from functional to more event-driven programming. For example, in the story, you are able to read while your friend checks the forecast (Promise) while with the radio on, you have to listen continuously (event-driven)

[dianavlasenkova]

Incredibly clear explanation! Thanks a lot!

[saragsamain]

It is great to (finally) find a clear explanation of Observables vs Promises and Subjects, thank you!! Great video:)

[earthpligrim]

this is the first video of yours that I have seen, i wish i found this like years back. This is purely gold and you got a special teaching style esp with anagrams I love it. Thanks alot for all the contribution you have made. :)

[nfheaven]

Now that is a concrete explanation of rxjs! Loved it ! Well done!

[DarkMetroid]

Very easy to understand after coming back to angular after a few years break. Helped bring me up-to-speed on observables quickly.