Stepping Through Recursive Fibonacci Function

Understanding why and how the recursive Fibonacci function works

[yanzeliu]

This is the most clear explanation I found !! It's really nice and helpful.

[marybandziukas]

Thank you! I have been puzzling over how this works for 2 days. Khan Academy always delivers a clear and completely understandable explanation. Mainly by use of colors and not skipping a single step.

[陈瀚龙]

This is the ONLY clear, clean, and thorough explanation of this algorithm, that I've found, on youtube or EdX. Thanks a million. You make it a good thing to shout

[anfrollex]

Best explanation ever, even math websites couldn't get to the point what it really wants. Perfect!

[julietonyekaoha]

I have been going over the recursive solution of the Fibonacci sequence for a day now and I couldn't figure it out, this explanation was clear and concise and I finally understood what is happening under the hood. Thank you so much.

[KDazee]

You are really a life saver sir. Your explanation was so clear I understood it in one try. Thank you

[nikkyujoshi]

This guy is the one of the best teacher in the world. With little touch of real humour in teaching, students could learn almost anything without any stress.

[martingracchus]

amazing, for 9 years this video has been granting clarification to aspiring programmers. I am learning how to use caching and hashtables to reduce the time complexity of this function but did not fully understand how the naive solution worked and how the stack handles all of the returned values and how they are actually added. this makes so much sense now, THANKS.

"The cobwebs are now removed" - artie bucco (anyone who gets this reference gets a like)

[max-pax]

I loved it. Most productive 5 minutes of my life right after conception and birth :)

[ikroac]

13 years after and this explanation of recursive function is still the better. Thanks a lot sir

[Occupiedmarkus]

11 years later, this is still the better video than the rest

[SrFrancia]

Very good explanation. Amazing that this video is 12 years and there isn't a newer one that explains it better

[alexandrafoot]

I went over my class notes on recursion several times and it just wasn't clicking, then 2:08 minutes into this video I suddenly get it like its as simple as 2+2. You are a skilled teacher and a gift to the world

[manish]

This is very clean and clear to visualize.
Our mind do not work on numbers/text, it works on visualizations/images

This how we would be thing about recursion in our mind. Thanks a lot for understanding our mind & making us understand too....

[abdulhk]

I did try to understand this for almost an hour. Not for this video, I really don't know how much more time was needed to figure this out. This explanation will further help me to unpack other programming aspects. Thanks a lot.

[anilbarad]

i have seen too many videos on this but this video has best explanation ever, great video, i am going to press subscribe button...thank you.

[amitdhawan]

I have watched quite a few videos on recursion but this one has explained it clearest of all. Thank you very much for this awesomeness!

[basedmangoes]

Amazing explanation Sal. I have looked through many videos that explained how to trace a recursive function with two calls in one method, and this one really takes the cake.

[zubairhasan]

THE BEST EXPLANATION!! I've been pulling my hair off how th does this recursive call works internally. Now I've finally got it.

[ozzyfromspace]

The mind bending thing about writing recursive code is the realization that all you’re doing is writing one function that returns a second function. The eureka moment comes when you realize that the second function could be anything, and in this case it is the starting function, perhaps with an algorithmically deprecated or advanced parameter. Then those base cases just show up to stop the code from running ‘forever’ (i.e. until your processor crashes). In a way, recursion is a way of nesting functions, and sure the values at each step have to be stored on the stack and there’s a whole bunch of clever stuff happening in the background, but essentially a recursion is when you write a program that calls itself later, in effect allowing you to build a loop of functions. I can totally see how this would be useful for generating trees and other linked data structures. Thanks for the explanation, Sal! When I was first exposed to recursive code in my freshman year, I didn’t understand it and I failed to see the relevance but now it seems more natural. Kudos to you sir, learning never stops!