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.
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!
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 RU-vid. 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 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.
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!
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;
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!
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
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?
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.
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)
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)
