Dynamic Arrays in C++ (std::vector)
Вставка
- Опубліковано 5 лип 2024
- Patreon ► / thecherno
Twitter ► / thecherno
Instagram ► / thecherno
Discord ► thecherno.com/discord
Series Playlist ► thecherno.com/cpp
Why is it called "vector"? ► stackoverflow.com/questions/5...
EASTL ► github.com/electronicarts/EASTL
Thank you to the following Patreon supporters:
- Samuel Egger
- Dominic Pace
Gear I use:
-----------------
BEST laptop for programming! ► geni.us/pakTES
My FAVOURITE keyboard for programming! ► geni.us/zNhB
FAVOURITE monitors for programming! ► geni.us/Ig6KBq
MAIN Camera ► geni.us/t6xyDRO
MAIN Lens ► geni.us/xGoDWT
Second Camera ► geni.us/CYUQ
Microphone ► geni.us/wqO6g7K
I love how you treat C++ like an actual language you'd speak in
Great set of videos!
I study computer engineering, and work with C++ for nearly all assignments. When there's issues with the code, I've been using these videos to get a deeper understanding on how a certain topic works, and it's been a huge help. Keep it up!
It will be so cool to compare one of the STL container (as an example) with one rewritten in the EA library and see the differences ;)
it will be 35$ extra for that DLC
better not to, BF2042 is one reason for that, game so broken that Engine so broken as well and plus extra charge for DLC, so good that Cherno left EA
@@Blonder_Studio he's too good, passionate and professional for them.
Brilliant channel man! Right now I have to implement an algorithm in an efficient way in C++ for my studies, your videos are an incredible help!
your videos are truly amazing. I wasn't able to catch up at first but now i really enjoy it and i am getting to understand more and more about c++ everyday
Fantastic channel! So great to get things explained by someone who actually knows what goes on behind the scenes, and who does not make absolutely everything into an programming analogy with food and animals.
10/10
Thank you! One of the best YT channels to explain simply difficult (at first glance) problems and especially put them into practice
Seriously, you are better than my instructors at explaining everything. You are better at explaining than the damn books. These trimmed down and non bloated explanations are so much better than what I have been going through.
Go boy, go! You're my inspiration for learning C++. Your videos and your charisma and attitude!
I double this. He's not like most of the other people that teach this stuff on youtube. Listening to most people is like listening to text to speech or Ben stein and watching pain dry at the same time. This guy will make my life if he avoids using the word GOOEY and says G U I like a normal human being.
@@MrSerozka Sure, they make up something that sounds retarded and takes more to spell than the original spelling for... reasons! Fuckin millennials..
I wonder after 4 years if you ever did learn c++.
@@mrbrian826 Yes, but I still don't use it as my primary language, practically for anything... I'm into C# at the moment
@@ytacctaccnt nice
I learned more watching this than a week taking my CSII course! Keep it up
Same
Man i'm so glad I found your channel, you're saving me rn
So much usefull information,u do not just give general understanding of a topic but provide the logic of its work
i am glad i found your channel
Up to this point it's not that I don't know all these, it's just I want to see how you program, because you have way better programming style than I did. Thanks Cherno!
Great stuff! The name confused me too when I first learned about std::vector..
11:34
Roughly speaking, abstract thinking develops over the years as a programmer which is a good trait so one doesn't have to stay longer into details like this.
Amazing channel, just found it. :) Also the first tutorial channel I have ever found that I do not listen to at 1.5X speed.
i need to slow it down sometimes i think lol
Thanks for putting so much effort into these videos.
Great video.
I learn so much from this guy. real talent.
I would like to learn more about the best practices of memory allocation.
It's called a vector because Alex Stepanov, the designer of the Standard Template Library, was looking for a name to distinguish it from built-in arrays. He admits now that he made a mistake, because mathematics already uses the term 'vector' for a fixed-length sequence of numbers. C++11 compounds this mistake by introducing a class 'array' that behaves similarly to a mathematical vector.
Alex's lesson: be very careful every time you name something.
So now we have a class named Vector that behaves kinda like an array and a class named array that behaves kinda like a vector...
Indeed, be careful when naming something
I learned a lot , thanks
pls keep it up and make some video about graph representation and boost library
This is amazing, man. I like your videos so much
Probably my favorite programming channel, Not only are his videos exciting, his style is so much cleaner. Best channel on youtube!
Yea he tends to dig a bit deeper than others :)
@@jannesopanen8032 here you are replying to a comment from a couple years ago, and I've already forgotten all I knew about programming.
Wow that was pretty well done. I think I got enough to try out my own sort of mini project.
Thank you SO SO SO MUCH BROOO! You don't know how you've just helped me... I understood every single thing you just said.😱👍👍👍
Yepp...
I was also confused with going from Unity C# vectors...
To the C++ version of vectors! XD
Nice video!
Very nicely explained and very informative!
Thanks The Cherno! Great explanation as always! 👍
Thanks a lot......clearly explained basics about vector(Dynamic Array or Array List)👏👏👏
Great video as always!
you are amazing at teaching, keep it up!
11:30 Thanks for addressing this finally... Coming from C# I saw the method signatures in C++ and thought "are humans supposed to be able to read this"
Thank You For Saving My Semester :)
it happened again. Near the end of the video, I thought someone else was playing music somewhere until i realized the source coming from this video...
very nice little class learned so much cheers!
Quality content! Thumbs up!
Subscribed! Looking forward to going over your videos on C++👍👍👍👍👍
at 9:48 if anyone doesn't understand how he initialized the struct you can search for "aggregate initialization".
Is it bad that instead of watching the video I'm just watching his hands?
No
explains pretty much everything
If I'm watching his hands, it's because he's getting close to backhanding the cactus.
That is the purpose of the video. The hand gestures are an advanced form of hypnosis that will make you understand vectors better.
I think The Cherno is secretly Italian ;)
You should mention emplace_back in another video.
You're a god with a compiler. Been programming in C++ for longer than I care to admit, and when I stumble across something I'm not 100% confident with I think "I wonder if Cherno can help me out here" and sure enough you can, and have, several times! Keep up the good work bud, VERY much appreciated.
11:40 C++ is love♥️
bro, you're too smart! goddamn, good shit
Very nice , Please make more videos on other data structures
Man, your concepts are so clear.
I absolutely love the comparison with Java, because I started out with Java in High School.
learning programmin in high school sucks balls
i learned c# in high school and my "teacher" is a piece of shit bad
great content !
please make parallel process and simd tutorial
你好，陈诺，你的课讲的太好了
"Simple spice series" very accurate caption
Nice video ; I'm really confused of these vectors in computer science if we needed a dynamic array we would use a linked list .
what is the difference between these two ?
To think I was modestly learning about pointers and jumped into this rabbit hole.
Can you recommend a book or course that gets more in depth information about behind the scenes of c++?
Coding and guitar
That's an awesome combo!
so i didnt know how the vector class worked, so i created an "ArrayList" class,
and i did the exact same thing that the vector class does xD to add an element just create a new array with current size + 1 and copy all of the previous contents into array[0 to size-1] and put the new element into array[size]
@Peterolen i know but it is sort of a simplified version of the vector and ArrayList. It has the same concept behind it
hey, what do you use to program in c++? Visual Studio? Awsome work ^^
Excellent!
Will be glad to see someone trying to rewrite a STL written thing which can be more optimal and more towards the personal use case.
Good job
Good video !!!
How we should use inline ?
if function are short we should use inline otherwise we shouldn't ?
In physics we can represent a vector as a row or column matrix( kinda like a 1d array ).
maybe that's why
I know this is about five years later, but another reason I've learned not to store pointers in vectors is that the element can be deleted from the vector leaving a memory leak. If you're using vectors with pointers, be careful.
I remember in Bjarne Stroustrup's book, he never talks about raw array, he just went a head and talks about std::vector.
Hm... While following along after making the Vertex class and attempting to print it to the console using
std::cout
does it basically work like dynamic memory allocation with malloc/realloc in c?
Dynamic arrays (mostly std::vector) is an array which can resize. You can push new things into it.
I have a question not related to the topic, why are classes in the standard library defined with lowercase identifiers, even though everyone declares classes with camel casing?
Yes, you are great!
your ccoding skill are great!
I envy you!
In linear algebra pne of the basic example of vectors is exactly what programmer would think of as an array or a tuple. So mathematically its quite natural to identify arrays and vectors as being very similar, if not the same thing
Please go in to data structures! All other videos is not even close your your quality!
Well i would like to see a video with data structures too, youtube lack of quality videos with data structures in c++.....
Data structures are supposed to be abstract and language agnostic, unless they need to meet a very specific need. But assuming you are talking about datastructures such as Queues, HashMaps and all that, the implementation is relatively the same. The only thing that might be a little different may be some fine tuning using your knowledge of the language to optimize some bits. But they should work the same way they would in every other language.
Knowing how one is implemented in abstract and knowing the language you are going to implement them on is the only thing you need.
Awesome.
Please make a video on STL in C++
Personal Notes:
-dynamic size, at the background it has limited memory but when reaches the limit, it creates a bigger sized memory and copies contents to it.
- #include
- std::vector vertices
To add: entities.push_back((1,0,0)) (must be implicit conversion)
- can use it in for loop:
for(Vertex v: vertices) { //do sth }
To prevent copying and being faster,
for(Vertex& v: vertices) { //do sth }
- to delete 2nd element: vertices.erase(vertices.begin()+1)
how do you access vectors of vectors? like in an matrix cause you can't exactly do matrix.assign() to a specific value can you?
At 8:50 there's a note about moving rather than copying. Is there a video about this in this series?
I tried to do this thing for like 4 hours in total, and now i learned there is library that does this. (wasn't able to do it btw, i got stuck on some exceptions and shit)
Nice video bud.
Thanks
hi could you tell us how to watch a bool vector in debug time?. because l did it for int and strings without problems
THE Best !
how can we make the function for import series data (around 5000points)?
Whats the difference between dynamic array and vector ? are they both the same thing ?
All the videos have in common that when you made a question and the answer is: "It depends"
luv u mate
Yet to understand why my professor decided to teach so much array stuff but said “vectors are the same so I’m gonna skip over them” when in reality, these vectors are beautiful works of art that shit on arrays lol. Simply the fact that they’re dynamic makes life so easy.
Can you do something similar in C or just the classic memory allocation commands?
Also, if I know the amount that I'm going to insert but it's defined by the user is it correct to declare the array like "Arr[nAmount]"?
@Peterolen yes, I know about them. The problem is that not every c compiler accepts the example I wrote in the second paragraph. In some microchips you simply can't give variable length, only memory commands.
I was writing a little game in c as a bit of a challenge and I had to write my own dynamic array. The way I did it was that you create it with an initial size, but when it exceeds the size, the size of the array doubles. That way I don't have to reallocate the array every single time I add or remove an element, but I'm also not using up too much memory.
I'm pretty sure that is what vectors do as well.
Fantastic \o
thanks
Can i use the vectors for struct with different data types
Good video, but if you have a vector of string, what can you do if you want the first character of a string?
From your video I learned Java and C#
张铁男 你是中国人吗？
As a front-end JS dev, 3 days ago I had not a care in the world for performance. Half way through this C++ playlist and my first thought on hearing how this works is 'Damn that must be expensive.' JS seems so basic now lol.
How do you init a vector with values, not push after ?
I tried casting an int to (std::vector::const_iterator) to use as argument for the erase function, to no avail. Anyone understand what happens when vertices.begin + 1 is used as an argument? It seems there is some conversion going on, right? Why can the '1' be used there without any problem?
Enough eye contact for today
i love you papi cherno
Great
If i have a pointer to a vector which then moves to a different memory address to due to resize does my pointer automatically point to the new memory address?
Hey Cherno!
I got a little question about passing the vector to a subfunction:
In the Video at about 12:50 you are passing the vector via Function(vertices);
I would have expected a Function(vertices&); to specify it as a pointer or a reference, basically.
In C, every array is automatically passed by reference, it will never be copied.
Is it in C++ depending on the parameters of the target function as it is a pointer in your example?
Would love to hear your answer as I am a C developer and sometimes C++ is still a little strange to me.
All the best!
Hi, and congrats about this video series. Pretty deep and, therefore, interesting even for those who actually use C++ for fun, like me, but not professionally. Memory understanding is quite difficult at the beginning so I really appreciate your effort to make it clear. I have a question though. You said that programmers can choose to make a Stack allocation or a Heap allocation inside a standard vector and there are reasons for both choices. Pretty clear to me, but: let's assume you have a practical case. Can you show us your personal thoughts that bring you to use one instead of the other option? I mean several cases where you choose one option instead of the other and why. For instance, is there a max limit in bytes after which you choose a Heap allocation? Thanks very much