How to determine or get array length (size) in C/C++

In this video I will show you a technique to automatically get the size of an array in C/C++ using sizeof operator without having to hard-code the value

Thank you for your support!

[Alexanderkermani]

So concise and informative. Really amazing job. I'm behind in my C++ class (because I went straight into second semester C++ class without the first semester one), and you, my friend, are going to get me through. Thank you for the vids!

[danielvalandra]

Mo you'er the man, not only are you a great teacher you are good at what you do; thank you!

[jerryleemelton]

Thank you so much! I come from a Java background and this was giving me so much trouble in C++.

[mikenewman]

Thanks for this video, just ran into this particular problem not too long ago lol started C++ a week ago, you're a life savor! SUB!!!

[playstore-hpvk]

that was awesome . I got the formula that I was seeking for. thank you very much for sharing this

[__hannibaalbarca__]

This work only on stack allocation, allocation in free memory it should be defined by user in some manner of vector stl .

[SideQuestingWithLorrie]

Beautiful explanation. Thank you so much!

[JasonKT]

wow thank you holy shit i was going crazy, like how the fk is the array size 12 if it only has 3 elements, u made it clear thanks

[DarknessGudeMe]

I see 2 problems with this:
1. what if a is of length 0, won't a[0] seg fault?
2. placing the macro in for loop conditional would make the evaluation at every iteration. (better to do it only once)

[SarozPradhan]

Thank you! The instruction is very clear!

[andrewpark]

what if we declare array[100] in the beginning and if we only input 15 values into the array, how are we supposed to get the length of the array? If I do that sizeof thing I will get 100, but I want 15.

[manoharnookala]

Hi, i have size like 20, and in the array few element(s) i have. then how to find the length. i dont want to count junk elements.

[DansonPiano]

is ar already known to be array? why does it work when u divide size of ar instead of size of a?

[K-Choi]

how about when I pass the array to a function and get the sizeof inside that function, how do I handle such thing that it won't decay, assuming that the parameter only accepts the array?

[lotpot]

so there's no any built function for that
? 😢

[aliahmad]

how can we find the size of a dynamically allocated array?

[ShekharGupta]

But if I pass this array as a parameter to some function, then how to calculate its length ?

[abcdefghijklmnopqrstuvwxy]

what is "stdafx.h"

Error 1 error C1083: Cannot open include file: 'stdafx.h': No such file or directory

[mrmanuel]

Hi, A bit confused on how your compiler is giving you 48 as sizeof(a); on my pc using the same code i am getting it straight answer e.g 10. Note: ignore my question i was actually using an unsigned char a[] instead of int a[].

[atata]

what is meaning of
s1=sizeof(*arr); ?