mergeMap vs concatMap vs exhaustMap vs switchMap | RxJS Tutorials

[@NamNguyen-yt4sb]

Damn, hands down best explanation I have seen so far. Thank you for your great work!

[@IndianKhanSameer]

Agreed!!

[@alinapostol2230]

Best explanation of mergeMap, concatMap, exhaustMap and switchMap, with super easy-to-understand drawings slides. Thank you for the effort you put into making this video!

[@none0n]

This is the best on this subject on the internet

[@meysam8357]

thank you for this tutorial this is the best tutorial i found to explain the flatten operators

[@rafiquemohammed3029]

After all these years... today i understood the map operators.. You man! You deserve a subscribe

[@TheRuiMonte]

Man, I've been looking into this map operators for days and only with you I've understood the theory. Thank you, really, thank you!

[@jsblade2770]

these maps are so intimidating to get into, thank u for the explanation

[@liedebunker1253]

I've watched a few, but only this one makes it clear! Thank you very much!👍

[@Cysecsg]

This explanation is much clearer than the big channels out there. We need visuals to understand things better!

[@CodeWithGio]

Absolutely, creating visuals takes a lot more time, but I find it impossible to properly explain different maps, without extra visuals. Especially when thinking about time and space, in which events happen asynchronously

[@jameswachira5713]

Excellent explanation. Good work sir

[@hgatl]

even it is longer than other shorts , he explains very well and Literally diagrams are far better than Rxjs Marbles . thanks for it

[@vanlongpham8874]

Best RxJS Map operators on KZbin.

[@mikhailratner4649]

This video brought me to your channel and made me binge watch your RxJS Playlist! So far, the whole playlist is handdown the best explanations of RxJS I've seen so far!!

[@oletrn]

Thanks for the great explanation. It's probably the best one I've seen so far (and I've seen many)! It's funny how after years of working with rxjs I still need a refresher regarding the mapping operators.

[@ianfoster232]

Amazing explanation! I have been rescued from the fog of numerous other videos and now have complete clarity. Thank you so much!

[@Fancules]

Perfect explanation, thanks a lot👍

[@mikheilmusaelyan]

ერთი 100 ვიდეოს ვუყურე და შენგან გავიგე, მადლობაა❤❤

[@OskrPulido]

thank you so much man!! Best explanation ever.

[@balunandam8006]

you're awesome, best explanation. Thank you.

[@udayprakash80]

super ... was looking for something like this .. keep rocking 😀

[@martytaylor2322]

Awesome explanations! Thanks.

[@wmjoers]

Best map operators tutorial ever! Thanks! :-)

[@viiskb]

Your slides are awesome. Thank you. Very nice explanation.

[@puyabahrani2250]

Thank you, very good explanation

[@ayushbhatnagar3889]

brilliant explanation. Thanks a lot

[@khoapham9529]

This is the easiest explanation to me so far :D. Big thanks!

[@256Ulises]

Muy buen video, la mejor explicación que he visto

[@dariooliveira5004]

Very helpful, thanks!

[@JBuchmann]

I have never used exhaustMap in practice, but I have always stuggled to to understand it. (probably why I have never used it). Thank you, your explanation finally made me understand it. I can only think of one real world use case for exhaustMap. Maybe a submit button that get hammered with clicks. When the first click is getting processed by the API, all other clicks (in the observable stream) will get tossed out. But I guess we could also prevent multiple clicks by disabling the button on submit, lol.

[@CodeWithGio]

You're right disabling the button is the easiest, I've personally rarely used exhaustMap, most of the time it's switchMap with http requests

[@sandeepdravidam7989]

After a long..... time, great to see you back!,try to do a video on declarative approach using Rxjs for a scenario

[@CodeWithGio]

I upload videos in every 2 weeks, that's what my schedule allows me at the moment. After I finish RxJS series, I plan to create some app angular+rxjs+nestjs+mongodb and cover various topics

[@sandeepdravidam7989]

@@CodeWithGio try to do the Rxjs videos based on scenarios rather than just explaining operators, functions,just like the city/pincode selection based on state, country etc ,scenario u took in one of your video ,these scenarios can achieved easily without the reactive approach,but when it comes to reactive dealing with Observables is bit tricky, testing is even tidous

[@GustavoGAvila]

Very good! Thank you!

[@ankitchandra6330]

best explanation ever !

[@danybohd]

great video, thank you

[@Constantine..]

Thanks for the detailed and clear explanation)

[@yosefrahahleh6796]

Keep going, you're awesome.

[@balaeinstein8710]

great sir . i dont think there are many good tutorials for rxjs in youtube . This one is going to be one of the very good rxjs tutorials . Please cover almost all the common and most used operators

[@CodeWithGio]

Absolutely, in the next video I'll make some practice challenge, using what we've covered so far

[@balaeinstein8710]

@@CodeWithGio thanks a lot sir .Hope this channel will grow very soon

[@lasham5248]

კაია!

[@SmL19902009]

Is there a map that is kind of a mix of switch and exhaust? Where if values arrive while the inner observable is processing, it will finish the current process and then continue with only the latest value received, ignoring the rest?

[@CodeWithGio]

If I understand question correctly you only want first two values processed? Then it's a combination of concatMap + take(2)

[@SmL19902009]

@@CodeWithGio not the first two, the first and last. Basically, say values 1 comes in and while it's processing, value 2, 3, and 4 come in (in that order). Once 1 is finished processing, I would want it to only process 4 (since it was the newest value) and ignore 2 and 3

[@CodeWithGio]

I think you need to create a custom map operator for that

[@samluo47]

Hello Gio, great video! Off topic, I am actually confused about the sequence of multiple pipes, for example, if I have merge map for my first pipe, then following with take(1), does that mean I only take the inner observable once? and it's literally different than putting take(1) for my first pipe?

[@CodeWithGio]

Hi Sam, not sure I understand, can you share some code?

[@samluo47]

I can see the difference moving take(1) down.. putting it before mergeMap will not complete the outer observable unless the inner is complete(why?) , but putting it below mergeMap will complete the outer observable right away when inner subject emit a value.

[@CodeWithGio]

I see, well think of it this way, mergeMap doesn't know when to complete by itself, it's a mapping function after all. So it looks for inner obs to complete (or not, depends on how inner is implemented). On the other hand take knows when to complete. In your example, whatever is down the line drives the completion of outer observable

[@samluo47]

@@CodeWithGio yes that makes sense! I tried posting my forked rxjs playground link here.. but it just disappear :((. thanks for you time anyway , keep up the good work, your video is 💯

[@vazhaabdu4529]

ძალიან კარგია

[@getdevotional]

Awesome! I love the explination. Would you please provide the source code of this video? It would be really helpful for me to practice.

[@CodeWithGio]

I'll try to create proper github page and put source files there

[@getdevotional]

@@CodeWithGio That would be very useful, thank you so much!

[@javierolazaran7227]

Take the sub good man

[@rafiquemohammed3029]

The only thing missing in this video is what happens if any one of the request get failed or never emitted anything. for instance Http failure.

[@CodeWithGio]

I've covered that in other videos, once error happens entire execution is halted and subscribers receive notification via error handler