ITERATORS in C++ 

Thanks for watching! If you're after more, try and conditionally erase elements from your data structure while iterating over it, and make sure it works! Also don't forget to check out Skillshare - the first 1000 people who click the link will get 2 free months of Skillshare Premium: skl.sh/thecherno0820

University: "As a CS student you will always have to learn the newest technologies." Also university: "Yea you gonna use c++-98, cause thats what the professor learned back in the day and he never bothered to update his lecture for 20 years."

Love how he mentioned university using c++ 2003 but I was using c++ 98 in my university and i graduated last year.

I was recently given a C++ assessment for C++03, this was the first time a company interviewed me for such an old version. Seems like certain companies still have 20 years to catch up.

Another excellent video! I wish I had these when I was learning this stuff. Even though most of these are not new to me I never miss a single c++ series video because they are so well done. Keep it up!

Me : What are iterators ? Cherno: Iterators are used to iterate . Me:....... Cherno: Sometimes my genius is ........ its almost frightening

As a JS developer learning C++, seeing the structured binding at the end made me smile. It literally looks the same, and in JS is called destructuring. Nice video

Another good reason to use iterators in basic data structures (that you could access by an index) is to have iterators with different behaviors e.g. a reverse iterator (trivial), an iterator that gives you the next random element or that accesses the elements in a specific order or that applies some filter function.

Note that the example with structured bindings will copy the elements. To iterate over a reference to the elements use: for (auto& [key, value] : map)

you make my self taught journey of c++ so much easier. Thank you so much

was waiting for this one!! Love this series, and that smooth sponsor transition

Brilliant tutorial on iterators, Cherno. Always good to have such refreshers!

Great! I was waiting for a good tutorial on this. Thanks Cherno.

This video is crafted overly well and i love it. Thank you for the thorough explanation of iterators.

You are too good man. Thanks for this, to the point and easy to understand, no bs.

This is one of the best explanations of iterators I have seen, I was banging my head around google for so long! thanks

Just started my journey of c++ by your playlist....am really really excited 😃

This video is still GOLD. Thank you Cherno. Really useful.

Excellent video, was worth watching the entire thing. Subscribed

Thanks a lot. I really like the way you explain the iterators. The examples are simple and clear.

Additionally, would be really useful to mention about the usage of the reference '&' for the iterator it self. I.e. instead of using "for (auto kv : map)" - using "for (const auto& kv : map)" would eliminate unnecessary copies when iterating.

You teach soo much clearly and go just one step deeper

absolutely amazing video. Each video of yours make me love the language even more. I use it a lot in embedded systems and they way C++ elegantly interfaces with the hardware is simply beatiful .

Great explanation, as always! Waiting for the next episode!

I feel kinda smug that my uni has made it all the way to C++ 11.

Awesome overview! keep up the good work!

i enjoyed watching every second of this tutorial. Thank you.

That's exactly the video I was waiting for !

For the video about iterators, an example about how it could be used for something different than iterating over a collection of element would be to iterate over a random class. Maybe you would construct with arguments about the range (min, max, number of values) and iterate through it, but the iterator would generate random numbers on the fly.

I fuckin love you. I was just looking for iterators and didn't find your video about it. Seriously, without you I would not have become as good as I am right now thank god. If I could sub to your patrion I would. Good luck with your work boi!!

I'm looking for this tutorial! Thank you for making this!

Thank you for still making programming tutorials (and hopefully more gfx!). I was afraid you wouldn’t after your reaction super stardom!

Hey Cherno. Just want to leave some feedback to your videos: You are the BEST!!! Thanks a lot for your effort. You make it so easy to learn C++ and you are such a great character with always perfect hair :D!

You made my day and just got a new subscriber

I have never seen or heard of C++17 structured bindings. I love learning new things about C++!

Thanks. I Was Looking For This

Yes! I've been waiting for iterators !

Hello! Great video! I think it would be interesting for you to make a video about how to implement a custom iterator for a custom STL compatible data structure (may be with some fancy algorithm). In the video you could touch something about template stuff and all these "using value_type = ", etc. Good luck! Looking forward to the new video!

Thank you. I learned a lot by watching your channel

Hey @TheCherno thanks for another great video! Can you also please make a video on different containers, and algorithms in c++, which are most commonly used.

As a side note, ++it is generally more efficient than it++. The postfix operator has to create a temporary under the hood in addition to calling ++it.

Thank you for clarifying this, which helped me make sense of it right away: Iterators appeared in the language because not all collections can be iterated over by an index.

Nicely done! Thank you.

Thanks, very informative!

I was just having a problem with this, thank you so much!

Thank you so much for this video

Expected to see operations between iterators, offsets and so on :)

nice work. As a student,i think that analyzing comlicated STL template design would be quite interesting.

Perfect introduction! Thx for that! You're doing really well ;)

It would be great to have a video on static code analyzers and sanitizers like address/thread sanitizers, cppcheck, sourcemonitor, etc.

I am going over this area right now at university. So this is an especially useful tutorial.

Make a short video of typing and shortcuts

0:27 yea and mine uses Turbo C which was released in 1993 when C++ wasn't even standardized

Congratulations for channel. Video is much fine. Thank you for teaching. Peace and Health

Thank you for the amazing videos :)

In a sense I felt like this was much more useful video for map than the actual map video. Or maybe I remember poorly. However I remember struggling with maps in 2018 or so. It was a terrible school task of STL containers where you had a nature park hiking routes with locations and you'd have to return the route with least elevation change between requested A and B. I'm still having nightmares from that, I just couldn't wrap my head around that. And another thing was nested maps... It was kinda funny to do the first C++ class in 2011 and the second right in 2018. A lot had changed but I had no idea, because even today the material for the first class is the same. The fundamentals don't change. So I guess I'd love to see more of those more advanced/complicated applications of these simple tools. Things that force you to think but also demonstrations of what's actually going on in there.

Thanks once again for a highly informative video! Is there any significant speed difference between regular indexing and iterators on ordered data structures? For example, when I have multiple for loops running over arrays/matrices, would it be faster to use iterators and de-reference pointers or to obtain the values by the usual indexing?

We used turbo c++ in our college before we graduated in 2021. Stuff that has not been used since 1996. It makes the students hate this language. I really hope they update their system and their syllabus up to the current technology. Never had a lot of fun there 😅

watch all the c++ videos in a week. omg Cherno, you somehow look young->old->young

This was brilliant.

Very nice video! As a junior developer it helps me understand my colleagues code xD

For those watching for a good reference book: C++ primer is the way to go(imo.).

Thank you for the 70+ videos and the 20 sponsors from skillshare

10:47 My man, rhyming. "I wanna iterate through it, How would I do it?"

Last for loop for map should be like below for( const auto& [ key, value ] : map )

As a recent CS grad, I never quite understand when people say "my university used x language or version", because my university assignemnts (especially final year) were mostly generalized to whichever language you wanted to use. Aside from certain exceptions - for example groupwork, and my mobile apps course was taught in SwiftUI on a specific version of Xcode, for logistical reasons - this was the norm. Did/are other students experiencing a different kind of CS degree, perhaps more practical and less theoretical? Additionally, what is the merit of constraining students in this way?

great lecture

thanks for the video. About the last two methods, is there versions of them to iterate to a certain position of the map and not to the full range of it?

Nice. Thank you!

hi cherno . are you planning to do a separate series of videos on c++ STL?

cherno literally saving me through online school

I am learning c++ with a book called C++ in One Hour a Day. And when i confuse, don't get something, i know where to go. Your videos are AMAZING. Hope that your videos can reach more people.

Is it also true that the iterator reduces the number of implementations in the algorithm library? I heard it allows the algorithms to traverse on any container type.

Awesome video

I'm really waiting for the exception in C++ class....

Nice video. Can you discuss the new features of C++20?

Thank you

Time warp - I remember trying to code a card game in Turbo Pascal during computer science in the year 1986/87 I believe. That was not easy at all.

thank you sir

For school I have to compile in C++ 98 😅 Really useful stuff! But i'll remember this video after my class.

My uni was C++11 last I took the classes. And I thought that was a bit outdated…

Note on Game Engine: I make my 'Game Engine' in Flutter/Node.js/Sql etc... I make it fully multi interactive say Yatzee full functions etc. Then i have idea it would be easy to replace the Yatzee with say Chess and if good game engine it would be more or less easy to implement. My real idea is that when games came about in the beginning most where full programs not much to backup change since each program is isolated. Forward Amiga came with operating system where games could use the operating system simplifying the game structure. Forward more things are given to the game engine so the switch between games made simple. My idea is that a good game engine provides all most important features so ease of new creation.

Please make a video of making a c++ class that's iterable and define all the required methods. Thanks

Hey Cherno, can you talk about the y_combinator and the best implementation in c++17?

10:45 Cherno: I don't use CPP, CPP uses me.

Iterators are used extensively in stl algorithms library.

I was told we are doing this is college because they have to show us the theory along with the way things actually work. You arent "supposed" to do certain things without knowing how they work first according to the colleges.

Thematically next would be ranges.

8:00 i would recommend you write ++it instead of it++ because its more efficient in iterators

This guy is saving my unilife

it's unbelievable how there's no documentation about this

Beautiful

Wish I knew about this 2 months ago. I had to write a compiler for class that used this everywhere. Normal when I write code, I already feel like a monkey on a typewriter trying to recreate Shakespeare. But after watching this, I think I need to burn and bury my code to atone for the shame.

auto is amazing

would love to give your thoughts on the hot chip 2020 for the Xbox Series X . i mean you talked about the great mark cerny presentation , now its Microsoft turn .

Cherno, make video about rust vs cpp and Point to the claims of the rust language that all other things can be applied to the Cpp. For example, writing code that adheres to smart pointers(unique_ptr) And shared ptr for secure concurrent context. My suggestion is to build a library that has all these things together under the name secpp, for example.

How would you implement iterators in templated functions (similar to many STL functions like std::sort)?

I can only say that I really like you and your class！🤒🥳

At 12:00, you can also use for(auto it = map.cbegin(); it != map.cend(); std::advance(it, 1)) {...}

Gold!