Bitwise operators and an implementation of a flag system using them. Link to our hexadecimal, binary and decimal conversions course over at skillshare: skl.sh/2WIk8JP Check out our Discord server: / discord
Thanks for the great explanation!! If i'm not mistaken you can also do a "flag toggler" with a xor operator between the flag variable and the flag to toogle: 10000011 10000001 00000010 ^ 00000010^ 10000001 10000011
Having studied at least 10-15 different explanations around the subject of bitwise operations, none really provided the "lightbulb" moment. Sure, all of those other videos explained what the operations did, and I was able to understand them, but this was by far the best example of what bitwise operations are actually useful for. After watching, I was able to come to this understanding on my own: Manipulation or assessment techniques of individual bits within an allocated memory space; used to efficiently represent states, properties or attributes of a system with the smallest allocation of memory required to do so.
Thank you for this. After years of programming, I've found myself implementing a websocket server specifications that require bit masking. Your video has helped greatly in understanding bitwise operations. Thank you.
Honestly, I have bought courses on udemy only to discover that there were better material available free on TH-cam. The only good thing that came from those courses is a well structured learning plan. I am not saying udemy courses are bad, I bought some and I have no regrets over it. I am just saying that sometimes, free resources are better!
I am learning how to send bit from client, server using signals. So I came to look for the bits thing that I had no idea how it works and this is so cool. Now I want to learn more. Thanks!
Your tutorial is truly elegant and informative. The concise video taught me a lot and I appreciate how this channel is full of hidden gems that help demystify complex concepts. As I am currently studying 'Computer Systems: A Programmer's Perspective', your work has been incredibly helpful. Thank you for providing such amazing content. I would be thrilled to see more on system and network programming. If you have any particular book or topics in mind, please let me know as I will certainly follow. Thanks again for your great work!
Thank you for this! So the benefit of utilizing bitwise operations is to be able to drastically reduce the amount of required memory in your programs. I originally started learning C maybe 9 months ago and decided to switch to Python. Then a couple weeks ago I discovered that it's much better to make Android applications with java instead of python. Now I've just came to the bitwise portion of my Java book and they don't describe why these would be useful. I seen some bitwise operations being used in some source code in C related to the pinephone and googled for a while and couldn't figure out what was going on. With the help of this video, now I can at least grasp the concept. So now I get it, at least somewhat Great video!
20:16 database example. Not only memory. You could store the bitflags into database integer field (instead of 32 separate boolean fields) which saves some space on disk too.
Thanks for the great video, clear and very well explained. After reading 2.9 of The C Programming Language, I was completely baffled. Now it makes much more sense.
18:30 ive been able to use bitwise operators next to the equal sign like with += or -=. it works.. maybe worth pointing out too. So you could write flags &= ~SECOND_FLAG; flags |= SECOND_FLAG;
Great content! I have a few questions tho. Do the macros take up memory as well? The minimum being a byte? Would is still be memory efficient with all those macros? Also, is this way of doing conditional branching more performant or relatively slower compared to a if (flag) { } I’m assuming it would be a little slow because the bits have to be manipulated first?
The important aspect to understand about macros is that they disappear after the preprocessor step so, everything that starts with # actually disappears before the compilation begins thus, macros never add to execution time only pre-processing time. That if statement would be a tiny bit less performant, for sure. But it's quite insignificant I think. Bitwise operations are some of the fastest executing in a CPU
On Linux you can simply do: gcc main.c -o main ./main For Windows you can try installing WSL or use the VisualC or other Windows compilers (like MinGW)
thanks There is a question using bit operation: Given a number n, find length of the longest consecutive 1s in its binary representation. e.g. Input : n = 222 Output : 4 The binary representation of 222 is 11011110. The most efficient method is bitwise operation to find longest ones. But it is hard for me to understand it.
In the video I used *x & 1* to check if the last binary digit of x is 1. If you use that with the right shift operation in a loop will get you the proper result.
Question: Is this something a compiler automatically does when a program has a lot of bools? Or do we have to manually implement this to save the memory?
I sincerely appreciate your content! I've visited multiple times and everything is so very clear and laid out well. Regarding your #definitions, is there any performance gain doing it your way vs having #define FIRST 1 #define SECOND 2 #define THIRD 4 ?
It won't affect performance when running the program. It *might* affect compile time... but just by a very small amount. So I think it's fine if you want to do it that way!
No. It should work the same. An unsigned int should be only 4 bytes on both 32-bit and 64-bit architectures. And the rest are just bitwise operations which are never affected by the architecture (as far as I know)
Thanks for the great explanation!!
If i'm not mistaken you can also do a "flag toggler" with a xor operator between the flag variable and the flag to toogle:
10000011 10000001
00000010 ^ 00000010^
10000001 10000011
Yes, that is correct. I may have forgotten to mention that. Good catch!
This is the most interesting tutorial I've ever watched since I was in my mother's womb. I love you...
Having studied at least 10-15 different explanations around the subject of bitwise operations, none really provided the "lightbulb" moment. Sure, all of those other videos explained what the operations did, and I was able to understand them, but this was by far the best example of what bitwise operations are actually useful for. After watching, I was able to come to this understanding on my own:
Manipulation or assessment techniques of individual bits within an allocated memory space; used to efficiently represent states, properties or attributes of a system with the smallest allocation of memory required to do so.
Thank you for this. After years of programming, I've found myself implementing a websocket server specifications that require bit masking. Your video has helped greatly in understanding bitwise operations. Thank you.
We won't get on udemy what we get on your channel. Thank you so much bro
Honestly, I have bought courses on udemy only to discover that there were better material available free on TH-cam. The only good thing that came from those courses is a well structured learning plan.
I am not saying udemy courses are bad, I bought some and I have no regrets over it. I am just saying that sometimes, free resources are better!
Thank you, I never knew exactly why I would need to use these
Good explanation.
You can improve maintainability with left bitshift:
#define FIRST_FLAG 1
Didn't think of that. That's a nice way to go about it
Wow! There is no better explanation anywhere else. So well explained, thanks
mind blown, at the same time very clear explanation 👍
This is mind-blowing. Guy explains things like a professor. No buts!
Really loved this explanation! Extremely clear and easy to follow.
Thank you immensely! It was very helpful to see the practical use of bitwise operations and not just how to do them.
Thank you so much for your effort, your channel is an invaluable resource
what a good explanation!!
Congratulations!
Thanks for sharing your knowledge!👏🏽👏🏽😁😁🏆🏆
lots of love to u. absolutely loved how you explained it by taking practical example.
I am learning how to send bit from client, server using signals.
So I came to look for the bits thing that I had no idea how it works and this is so cool.
Now I want to learn more. Thanks!
minitalk
I'm starting with low level programming, and this is an awesome explanation, thank you for sharing your knowledge!
A true Engineer you are the best. Thank you for the explanation. It was very helpful
this channel it pure gold. I'm programming something for my company and this is so useful. generally this is gold.
After 20 years of learning this I finally understand the usecase .
Your tutorial is truly elegant and informative. The concise video taught me a lot and I appreciate how this channel is full of hidden gems that help demystify complex concepts. As I am currently studying 'Computer Systems: A Programmer's Perspective', your work has been incredibly helpful. Thank you for providing such amazing content. I would be thrilled to see more on system and network programming. If you have any particular book or topics in mind, please let me know as I will certainly follow. Thanks again for your great work!
This is beautiful. Thank You
Sensational video! Wow!
Fantastic video, thank you
Excellent video. Thank you
Amazing explanation! Thanks!!
Thank you so much for such quality material 😁
Thanks for this great video 👍
Superb description.
So well explained! Thank you
This video is pure gold.
Thanks for this amazing explanation!!
Wonderful step by steps @15:23 !
Thanks for the good video!
THANK YOU MAN YOU REALLY HELPED ME TO UNDER THIS TOPIC AND IMPLEMENT IT IN MY PROGRAM
very helpful and interesting, thanks!
Just found out C# has this feature too. Very nice for storing multiple enum values in a single variable.
Thank you for this!
So the benefit of utilizing bitwise operations is to be able to drastically reduce the amount of required memory in your programs.
I originally started learning C maybe 9 months ago and decided to switch to Python. Then a couple weeks ago I discovered that it's much better to make Android applications with java instead of python.
Now I've just came to the bitwise portion of my Java book and they don't describe why these would be useful.
I seen some bitwise operations being used in some source code in C related to the pinephone and googled for a while and couldn't figure out what was going on. With the help of this video, now I can at least grasp the concept.
So now I get it, at least somewhat
Great video!
20:16 database example. Not only memory. You could store the bitflags into database integer field (instead of 32 separate boolean fields) which saves some space on disk too.
Thank you sir, very well explained
excellent explantion
Thanks for the great video, clear and very well explained. After reading 2.9 of The C Programming Language, I was completely baffled. Now it makes much more sense.
I was in the same boat
Thanks - excellent explaination
Thank you. This is very helpful
the youtube example really helped great work
Very helpful thank you.
Super Super example. Thank u
amazing explanation🔥🔥🔥
Purrfect!
your explanation is so clear my professor can't explain me
Thanks man!!
I love you man grat tutorial
thank you
thanks
Brother ❤❤
love u
18:30 ive been able to use bitwise operators next to the equal sign like with += or -=. it works.. maybe worth pointing out too.
So you could write
flags &= ~SECOND_FLAG;
flags |= SECOND_FLAG;
Good point!
❤❤❤❤
I just have to make a double comment because this is niceeeeee
Great content!
I have a few questions tho.
Do the macros take up memory as well? The minimum being a byte? Would is still be memory efficient with all those macros?
Also, is this way of doing conditional branching more performant or relatively slower compared to a
if (flag) { }
I’m assuming it would be a little slow because the bits have to be manipulated first?
The important aspect to understand about macros is that they disappear after the preprocessor step so, everything that starts with # actually disappears before the compilation begins thus, macros never add to execution time only pre-processing time.
That if statement would be a tiny bit less performant, for sure. But it's quite insignificant I think. Bitwise operations are some of the fastest executing in a CPU
Thanks, i guess next video should be about bitwise shift operators
We've already uploaded a video about them: th-cam.com/video/lvjW-aUcbF0/w-d-xo.html
@@CodeVault I followed from a certain point the tutorials that's why i didn't notice, silly of me, thanks
Thanks for the explanation. I have a question: How do you run your c code in cmd instead of terminal's vs code ? Thanks again.
On Linux you can simply do:
gcc main.c -o main
./main
For Windows you can try installing WSL or use the VisualC or other Windows compilers (like MinGW)
thanks
There is a question using bit operation: Given a number n, find length of the longest consecutive 1s in its binary representation.
e.g.
Input : n = 222
Output : 4
The binary representation of 222 is 11011110.
The most efficient method is bitwise operation to find longest ones. But it is hard for me to understand it.
In the video I used *x & 1* to check if the last binary digit of x is 1. If you use that with the right shift operation in a loop will get you the proper result.
Question: Is this something a compiler automatically does when a program has a lot of bools? Or do we have to manually implement this to save the memory?
I don't think any of the compilers do such an optimization. But I'm no expert in compilers so more research is needed regarding this
I sincerely appreciate your content! I've visited multiple times and everything is so very clear and laid out well.
Regarding your #definitions, is there any performance gain doing it your way vs having
#define FIRST 1
#define SECOND 2
#define THIRD 4
?
It won't affect performance when running the program. It *might* affect compile time... but just by a very small amount. So I think it's fine if you want to do it that way!
If i use this for a 32 bit application if i then update that application to 64 bit will everything break ?
No. It should work the same. An unsigned int should be only 4 bytes on both 32-bit and 64-bit architectures. And the rest are just bitwise operations which are never affected by the architecture (as far as I know)
| = bit setter
& = bit clearer
~ = bit toggler
you can tell a good explanation when before thr person gets to the punch line u can see where they are going already!
thank you