You're very welcome, I'm so glad to hear these videos are helping you! 😀

Where are u studying?

That’s so great to hear, thanks for sharing this, and you’re very welcome! :-)

That's awesome, I'm very glad to hear this video helped you out. 🙂

You're very welcome, I'm glad you enjoyed the video! :-D

You’re welcome Alex, I’m glad the video was able to help you out! :-)

Thank you for the kind feedback Christopher, I’m glad you enjoy the videos! :-) The channel has only been active for 2 years, I’m hoping over time more people learn about it too.

I’m glad the video was helpful for you, and thank you for the kind feedback! :-)

You’re welcome! :-)

You're very welcome, I'm glad to hear you were able to follow along and that you enjoyed the content! :-)

@@PortfolioCourses Whoops, to clarify, this comment was meant for your Stack ADT and operations tutorial!

@@dangeerraaron Oh ok that makes sense. 🙂

You’re welcome Ashenafi, I’m glad the explanations cleared things up! :-)

Thank you very much for the kind words, and I'm glad you found the channel too! 🙂

That's excellent to hear Yiğit! :-)

I’m glad you enjoy them Doruk! :-)

You’re welcome Alvaro! :-)

I’m glad you enjoyed it! :-)

cliff-hanger

You're welcome! 😀

You're welcome, I'm glad you enjoyed it! :-)

You’re very welcome! :-) I’m really glad to hear you enjoyed the video.

You're welcome! 🙂

Thank you Olamide! :-) Once you’ve allocated space for the array with malloc filling it with user input is the same as a regular array (“on the stack”), this video might help you with that: kzfaq.info/get/bejne/a9SpgMVozbCbiKc.html

@@PortfolioCourses Thank you for responding. I feel so honored. I'll try it and get back to you

@@D_Ladybug You're welcome. And cool sounds good! 🙂

#include #include int main () { int i, n; int *a; printf("Number of elements to be entered:"); scanf("%d",&n); a = (int*)calloc(n, sizeof(int)); printf("Enter %d numbers: ",n); for( i=0 ; i < n ; i++ ) { scanf("%d",&a[i]); } printf("The numbers entered are: "); for( i=0 ; i < n ; i++ ) { printf("%d ",a[i]); } free( a ); return(0); }

You're very welcome, I'm glad you enjoyed the sample programs! :-)

You're welcome! :-)

Thank you very much Philipp! :-)

You're very welcome! :-D

You’re welcome! :-)

Thank you Ishimwe, I'm glad to hear you enjoyed it! :-D

You're welcome Emanuel! :-)

I'm not sure Muhammad. I think you should get the same result. The original code is available here: github.com/portfoliocourses/c-example-code/blob/main/dynamicmem.c. That said, while free() is not required to alter the free'd memory (e.g. setting all the memory to zeros or random data), I don't believe there is anything stopping the compiler/OS/etc from doing this either. So if your using the exact same code and getting a different result, it may be due to the compiler/OS. :-)

@@PortfolioCourses Thank you! The os may have an effect on the result

@@muhammadaushafalfarras2485 hi! I got the exact same problem. [0]to [3] gets random numbers or 0's and after [3] it gave me the correct answers. Did you able to solve the problem?

Great question Nathan! :-) And yes, that's the idea. realloc() doesn't always need to copy the old dynamic array to a new location though, it will do that if it can enlarge the exist block of memory at the existing location in memory. If it does need to move the block of memory to a new location, it will copy the data, and it will free the 'old' area of memory for use again. Interestingly though, it may not CLEAR this block of memory, so whatever was there before, like passwords for example, will remain there. You might find these videos interesting: realloc basics: kzfaq.info/get/bejne/rNhnpKaCsdi5pGw.html realloc security vulnerability: kzfaq.info/get/bejne/lbSjY6aIqtW2maM.html handle realloc failure safely: kzfaq.info/get/bejne/qdGhdtGZzaeUio0.html

You're very welcome! :-)

That's a good question Arthur and to an extent the answer is that "it depends on the compiler". :-) Often how exactly a program compiles or is setup to execute isn't something that's part of the language definition, so it's left up to the compiler makers to decide. It can also vary from one platform (OS, hardware, etc) to the next too. So while it's a good question, I'm not sure I can provide a great answer. I think learning about compiler and OS design would help to answer these questions though.

I think some of that depends on the OS / architecture. But memory can definitely become "fragmented" with lots of gaps and whatnot, depending on what you're doing.

Wow thank you very much! :-)

Great question! :-) Yes, we don't need the typecast in C because malloc returns a void pointer. In C++ we do use the typecast: stackoverflow.com/a/3477952.

@@PortfolioCourses Ohh thanks!! That part had me confused since C++ does int* arr = new int[n]. Love your videos by the way, trying to learn C before college classes start!!!

Great question! 🙂 In C it is not necessary to typecast, but in C++ it is necessary. If you are using a C++ compiler, that might be the reason you get an error.

@@PortfolioCourses okay thank you so much!

@@marbles5590 You're welcome Shannen! 😀

C++ has pointers and OOP. :-)

Java needs an interpreter, it doesn't run natively.

I'm not sure what languages those systems are built with. It wouldn't surprise me if they use something "safer" than C, but I don't know. Assembly can be faster than C, but it can also be slower because compilers can be "smarter" about optimizing code execution than programmers sometimes. :-)

You're welcome! :-) The short answer is that the first one is declaring an array on the stack, the second declares a pointer variable called 'a' that will "point to an int". What this means is that it will store the memory address of an int. The malloc() function will allocate enough bytes to store 10 int values, i.e. it will go out and get block of memory large enough to store 10 ints. It returns the memory address of this block of memory, and that gets stored into the variable 'a'. We call this a "dynamically allocated array" and it gets stored in a different place in memory than the stack called "the heap". Learning more about pointers can help to learn about dynamic memory allocation: kzfaq.info/get/bejne/aK10nLt4mrjKfnk.html.

@@PortfolioCourses So many thanks to you, great teacher :) You are my most favorite teacher in youtube on my journey of becoming software engineer. Thanks a lot for everything

You're welcome! :-) And thank you so much for sharing such kind feedback, that means a lot to me!

You’re welcome! :-)

Like we it's not reasonable to use it in calloc because this function makes us sure that it is already clear.. but otoh there are some reasons to use it in malloc? I want to make sure that I understand that :)

Hi Adam, whether setting a pointer to NULL is a good practice or not is something people argue about a bit: stackoverflow.com/questions/1025589/setting-variable-to-null-after-free. :-) I would say that it's a good defensive practice to ensure that other parts of the program can check that the pointer is NULL (i.e. not being used to point to memory at that moment), but it may not really solve the problem it's trying to solve. People generally set the pointer to NULL after free to prevent trying to free the memory twice, but that usually occurs when we have multiple pointers to the same position in memory (e.g. by copying a pointer value to another variable) and then we try to free it two times using two different variables that store that address.

If you want to learn about malloc vs calloc this video may help: kzfaq.info/get/bejne/ibFyodt01pmspoE.html. :-)

It's a feature for glowies to install malware on your devices

Just so the video is focused on code, I go to the view menu at the top, and then the appearance submenu, and then I turn off all the different panels. I make the font bigger, though exactly how big depends on the video, that can be done by searching for 'font' underneath settings. And I use Terminal on MacOS, I just have the terminal next to Visual Studio Code on the right. :-) And I'm very glad to hear this video helped you out!

No because c,d are variables which are supposed to store the numbers given as arguments when the function is called.

​@@0xRAND0M Yeah, and the numbers given as arguments when the function *myfunction* is called in *main* are 4 and 7 respectively.

Thank you! :-)

Great question Nathan! In this video I am using Visual Studio Code. I have disabled some of the standard windows though that allow you to select different files, because in the videos I only want to focus on a single code file (most of the time anyways). The terminal is the other program I am using... the equivalent program on windows would be the command-line (though there are more sophisticated Windows terminals/shells, such as power shell). Maybe one day I can make a video on setting up exactly this 'environment' on Windows and/or a Mac. :-)

That's true, the illustration on the left was more about showing the idea of "the stack". 🙂

Hahaha 🙂

I don’t understand your comment, are you just repeating what’s discussed in the video? Or do you have a question? Because in the video I say multiple times that save is storing the same memory address as a. And yes, we don’t get different data from save or a because they are pointing to the same thing. :-)

​@@PortfolioCourses sorry my mistake , I just get confused when I copied this program on my pc i din't get same output, I got some garbage data, not the same as you .

Oh OK I see, thank you for the update I was curious. :-)

The code in the video will not cause your computer to crash. :-)

@@PortfolioCourses I swear my screen completely went black from doing it on vs code. I did the 10000000 though. Only thing I could do was reset my pc.