Explaining Pointers Until I Go Insane 

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If a codebase has any of this stuff, you'll know it's been backdoored.

Aight I'm never listening to the word "pointer" again

"say pointer again" "fuck you"

Honestly, An array of functions sounds pretty dope. Nevermind, an array of pointers to functions sounds pretty dope.

I honestly never had any issues understanding basic and more advanced pointer stuff, but THIS is some actual good stuff LMAO great video

You realize how complicated pointer syntax is when the best explanation of how to read complex statements is in a funny YT video

Who the hell would write the last one, without questioning their lives decisions.

It all can get stupidly complicated as we've seen, but the syntax follows simple rules: 1. start reading from the identifier out 2. favor [ ] and ( ) over * int (*(*x)[ ]) ( ): - Following rule #1, we start at x x - The identifier x is alone in parentheses with an asterisk, so it is [§1] a pointer *x - Outside of the parentheses, we follow rule #2, so it is [§2] an array (*x)[ ] - We're left with an asterisk inside the parentheses, so [§3] pointers *(*x)[ ] - Outside of the parentheses, rule #2, [§4] functions (*(*x)[ ])( ) - The functions return [§5] int putting §1, §2, §3, §4 and §5 together: x is (§1) a pointer to (§2) an array of (§3) pointers to (§4) functions that return (§5) an integer Once you got the hang of it, you can rewrite the example like: * [ ] * ( ) -> int And stitch things together in a way that makes sense. "->" means "returns" and it's optional/redundant (anything immediately after parentheses in this notation is a return anyway) Take the example of 5:34: [ ] * * (* char, * (* char) -> * int) -> [ ] * (* * char, * ( ) -> * char) -> * int Array of pointers to a pointer to a function that takes (a pointer to a character and a pointer to a function that takes (a pointer to a character) and returns a pointer to an integer) and returns an array of pointers to a function that takes (a pointer to a pointer to a character and a pointer to a function that returns a pointer to a character) and returns a pointer to an integer It looks insane, but it's not that difficult to wrap your head around if you're writing it following those two simple rules

to whoever reached a point in life where you ended up here or doing this, i really hope you find inner peace one day...

im actually glad i found this video, you explained this well and now i know how to interpret those long lines

C's syntax makes things excessively hard to parse, in other languages like C3 or more Pascal style languages (like Go and Odin) it's much more clear how these declarations compose

bro lost me before the ad break 💀

I think, most of the confusion comes from the syntax. For example, int (*(*x)[])() in Rust, would be Box> "Box" is Rust's pointer i32 is Rust's int

I finally understood. The type signatures are provided not the obvious way around, but outside in. For example: int x() is a function named "x", returning an integer. But instead of "x", I can put something different and it will mean, put the whole function inside whatever is in that position. For example "int (*x)()" means to put the function inside the *x. So It's a pointer to a function. But it's not just functions, it's **everything** if we analyze the "int (*x)()" again we get: int , which means to put the integer inside something that something: () It's a function! which means, that we put our int iside the return paramater of that function what's something: * it's a pointer! which means, we put our whole function with integer return type into a pointer. that something: x It's a name "x" which means, we put our whole pointer to a function with a return type of integer into the name "x" Let's do another example: char *(*(*(**x[])())[])(); it's a char, which is in a pointer, which is in the return type of a function, which is in a pointer which is in an array which is in a pointer, which is in the return type of a function, which is in a pointer, which is in a pointer, which is in an array, which is in "x"

"For example, if I use this struct 'Fucker'" caught me completely off guard XD My main takeaway from this video though is that as a C# dev for Unity, I shouldn't touch C++ with a 5 foot pole or else risk entering pointer hell.

this is what I understood from 3:10 - arr[0] -> func1 => int1 - arr [1] -> func2 => int2 x ->arr - arr[2] -> func3 => int3 - arr[3] -> func4 => int4 - arr[4] -> func5 => int5

6:00 Bro is holding the entire class inside his variable definition The God Variable.

I REFUSE to understand this syntax.

The fact that C lets you write stuff like this makes me think that someone forgot to write it as an entry in the Geneva convention

Man, It felt awesome and confusing at the same time, but thanks to you I come to know the different use of pointers.

That line of code in the thumbnail alone drove me insane and I haven't even watched the video yet.

"Go insane?" GO MENTIONED RAAAAAAAAAAAAAAAAAAAAAAAAA

0:14 as soon as i read "france" i subscribed and liked the video

In older computers, especially Lisp machines, pointers always came with a size. A pointer was a 2-D object to the hardware. It had a location, and a size. The weirdness of C/C++ pointer types is an attempt to recapture some of the elegance of earlier hardware in a later era where the hardware forgot about data safety.

Such an awesome teaching style!

Entertaining and very educational for me. Seeing different uses of pointers that you tried to demonstrate and describe them made my me intrigue, but at the same time dizzy. 😂

I FINALLY GOT POINTERS after more than 15 tutorials and another 15 "explanation" videos, you somehow made my brain click. Thank you so much!

what I get from this is that the song at the end rocks.

I think this video actually made these easier to parse.

A programmer goes to therapy. Therapist: Please tell me what you are scared of. Programmer: I am scared of pointers. Therapist: Okay, let me give you an array of pointers to handle them. Programmer: 😱😱😱

Ok how was this convoluted mess the thing that actually taught me how pointers work lol

This video made me cry

Your memory view and c debugger in vscode look very nice. Could you do a video on how you set this up or just gimme some info lol im jealous.

Actually the best explanation of these bullshit functions I’ve seen, thanks!

My favorite programming channel

What i learned from this video is that function pointers are pretty cool! :)

Understanding pointers, is like the Great Barrier between amateur devs and the pros! Because THIS is a concept in which knowing how computers actually works, helps tremendously!

"getting into programming is easy" the programming in question:

I buried this nightmare 20 yrs ago. After watching I'm sure I'll get one tonight.

A pointer consists of: 7, 9, 9, 9, 9, 9, 12. I.e. 7 bits unused, 12 bits for the physical offset in memory and the 9's are offsets into a page "tree" if you will . Most CPU's today only use four-level pages, so the top 16 bits (instead of 7) are unused - but Intel is starting to use five-level pages too. It's also why pages are 2^12 (4096) in size, and why large pages can be 2MB (2^(12+9)) and 1GB (2^(12+9+9)) respectively. You can cast a pointer to a number, and shift the bits into different values to clearly see how there's a clear pattern when you allocate memory etc.

Omg I never understood pointers so well as I do right now thanks to this video

I seriously never could imagine insanity up to this level.

"Great, you've explained these quite well. Now use them."

Came to learn about pointers, returned with all my braincells drained. 10/10

1. Love the suffering 2. Love the use of digimon story cyber sleuth ost, its suitable considering the BS that is the digivolution tree. 3. Great video

I understood 80% after 15 min totally

Should've mentioned the right-left rule. It's an easy algorithm to follow when trying to understand complex declarations like this.

awesome. dude I need your fonr and vscode thee right now

ohhh, i get it, thx :D. Finally understand pointer in my 3rd year in uni :)

you shoud have mentioned operator precedence. and also thr syntax related to those concepts perfectly fit into english grammar. as a Türk, ı can say it in english (up to some point) but cannot think of its meaning because we build up the noun phrases other way around

Those complex function declarations make me think of complex relational database.

Absolute heater 🔥🔥🔥🔥

I think that this is 100% the reason for the existence of the typedef keyword

Hi, you have been found in my recommendation :O I'm watching it only 0:32 and already subscribed you. You have a funny sense of Humor btw xD.

How did you not go insane sooner?!!?!?!???

This makes me thankful for the C# syntax

also all this pointer magic can be neatly swept under the rug if you use a lot of typedefs with proper names, makes the code much easier to understand for everyone

love the soundtrack

The way i look at it is, the way you declare a pointer, is the way you access it. So if you got int *(*p[]), you'd access the innermost value (being the int) in the same way: *(*p[i]). And then you work your way backwards To make the point(er) clearer ill go through this. So you access the int by doing *(*p[]), so *p[] is an array of pointers to int, and *p points to an array of pointers to int, and p is a pointer to an array of pointers to int

Pro Tip: Just add another */& or put around parentheses until you get no compilation errors.

you know it's bad when you have scan around the screen to find what the variable is even called

You had me at "Fucker". Subscribed.

Even the parser gave up, and he's still going

I wish this was a joke of some kind, then I wouldn't want to cry

somehow this made me understand pointers better than 4 years in uni

bro got every meme in his vault

Small clarification: you're never pointing to an array, you're always pointing to the location where your array starts.

There's probably already been someone saying this, but at 1:09, the allocation for the FUCKER variable was technically not correct, since alignment could see the struct end up larger than the raw data it contains. For instance, if we used an int after the char[6], most compilers would add a 2-byte padding before it to ensure that the address of the int is divisible by 4 (size of a 32 bit int which I assume is what int is) In general, the safest option is to always use malloc(sizeof()); it'll give you the correct size the compiler will assign your structs

Interfaces are a fine abstraction from function pointer madness

Unirocanically very useful video. Mad respect at the dinosaurs who invented C lol

I like your vids a lot!

On one hand, class/module structures and delegates are basically pointer stuff in pure C. In higher languages, these things 'look' much simpler, by simpler it means the context now spans several .cs files. :P On the other hand, your professor could give you a snippet of ASM code, and ask something like: provide an (or the most restrictive) equivalent C function signature of a CALL function in the code. Yes, you shall use "mov dh,word ptr [eax]" to figure out that eax is a pointer to the value dh now holds, and the only use case of the value being "test dh,dh" means eax can be a *byte, or *bool. :'D

3:29 --> See line 15 (3:21) for further clarification. In short, line 25 is saying that you want to first dereference the pointer, followed by selecting the function at index 0 for that pointer; then you have to de-reference that index (the array itself decays to a pointer containing the addresses of each function) in order to call the function you want from that double pointer. i.e., createFunctionPointerArray() returns "& -> {&add, &subtract}". You're making an embedded function library, I guess you could say, that the variable references, and you have to dereference all those pointers to access the function you want. Easy to understand?

Now I'm seeing stars everywhere.

interviewer: Great, add it to our interview question list!

I have been working professionally with C for well over a decade. I know most of the ways it can bite. If I see any of these in production, I'm burning the codebase and walking away, and so should you.

I can't believe I actually was able to solve the last two after fumbling on all the previous ones (mainly because of parenthesis which changed if x was a pointer to an array or an array of pointers). I think I'm cursed now.

The biggest problem with pointers is batshit insane C syntax.

Good Job, I have gone insane.

explaining GO pointers till i GO insane

Bro what's your vs code theme it looks nice

What font do you use ? that font is so cool !

Please do a vid of how you got that view of memory!

“Explaining pointers until I go insane” yeah 6 minutes took u way longer than I expected

I'm having PTSD from university every time you say pointers more than 2 times in a row

Ngl i actually understand now thanks 🥰😂

How to open that memory view in vs

i like your funny words magic man

A simple hack to read c types is to start from parenthesis and then read from right to left. So if you see something like int (*x)[4] its: *x - x is a pointer -------------------------^ [4] - to an array with length 4 -----------^ int - to an int ---------------------------^ Another example: int (*x)(char (*t)[4]) we start with parenthesis so x is a pointer then to the right we see another parenthesis so x it is a pointer to a function then we parse the arguments so the function takes a pointer t to an array of length 4 of chars an the original function x points to returns an int

Is that the all-too-common array of arrays length 8 of pointers to functions returning pointer to array of pointers to char? (The order is name, sufix, prefix, and operators on a name before sufix brackets (i.e. function argumrents) infer that the function is what is being stored in that way, after that is what is being returned; this necessitates that the type before the sufix brackets be a pointer as anything else C wouldnt know how to store) (Also the question would not parse, let alone make sense, you declare an array of arrays of undefined length, thats not allowed, if it was itd be an array of arrays of pointer pointers to functions returning a pointer to arrays len 8 with pointers to int) Or, in simple terms, its probably a number. Tldr just use c++, rust, java, python, ets. C is for pointer tricks and programming elevators, not for actual use. Unless you're making an OS, then it may come of use. C walked so that higher level languages could run.

I came into this, expecting to learn how to read that stuff. Sadly I don't think I learned anything (except maybe reading the decl from the inside outwards?). This video was entertaining though. Just to give you feedback

1:10 I'm pretty sure you can also use sizeof() directly instead of calculating manually

At some POINT I've stopped perceive word "pointer" as some meaningful entity and instead started to interpret it as some weird IKEA furniture name

Ok i need revisit some pointer videos before understand this

This actually made me understand pointer expressions. Thank you.

Hey man great video, but what is ypur extensions for memory looking and your theme

This video is amazing

Idk what the fuck happened to me but i was laughing like a fucking psycho everytime i hear the fucking word POINTER.

To create a program that parses a C expression and translate it into a sentence would be quite fun to do