How to create functions with a variable number of arguments using stdarg.h | C Programming Tutorial

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  • Опубліковано 19 вер 2024

КОМЕНТАРІ • 141

  • @A.E.B.
    @A.E.B. Рік тому +12

    Just want to say thanks for all your very clear and informative tutorials. I stumbled upon your channel for a specific C question and now am binge watching all your C videos, they're awesome!

    • @PortfolioCourses
      @PortfolioCourses  Рік тому +1

      Wow thank you so much for the super thanks Arne, and I’m so glad to hear you’ve found the channel and are enjoying the content! :-) If you come across a topic that the channel is not covering that you think it should, please feel free to let me know with a comment.

  • @benjminrichie
    @benjminrichie 10 місяців тому +4

    i havent even watched up to 5minutes of the video yet but i am already get the concepts.
    You are really amazing in your teaching method

    • @PortfolioCourses
      @PortfolioCourses  10 місяців тому

      I’m so glad you enjoy the teaching method! :-)

  • @mohammedosman6735
    @mohammedosman6735 Рік тому +23

    Thank you very much, very smooth and clear explanation... Definitely one of the best C tutorials on UA-cam.🥇🏆

  • @isaac-victorprovidence9047
    @isaac-victorprovidence9047 Рік тому +5

    I have a team project tomorrow, where we have to create our own print function to take care of the different function specifiers. This video just helped🥺. My go-to channel for all things coding 😊

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      That's awesome, I'm glad to hear this video helped! :-)

  • @atarixle
    @atarixle 7 місяців тому +3

    Hell this opens my eyes. I never noticed that printf's placeholders not only give the output-format, but also give the number of arguments to the functions.

  • @bilaledu9206
    @bilaledu9206 2 роки тому +13

    Beautiful and clear video! Step by step and understandable.
    Your videos help me make up for what's missing and build on what I've learned in class. Thanks a lot!

    • @PortfolioCourses
      @PortfolioCourses  2 роки тому +2

      You’re welcome! :-D Glad to hear you enjoy the videos.

  • @ijeomachimdimba2757
    @ijeomachimdimba2757 2 роки тому +2

    very easy to flow with your teaching, love this thank you

    • @PortfolioCourses
      @PortfolioCourses  2 роки тому

      Thank you very much Ijeoma, I'm glad to hear you enjoyed the video! :-D

  • @ሰውመሆን
    @ሰውመሆን Рік тому +1

    thank you so much. we are all grateful that you are providing all these great lectures for free🙏🙏🙏🙏

  • @kitsunevuon
    @kitsunevuon 11 місяців тому +1

    Boi, you just saved my cpool's first project.

  • @akosyt4540
    @akosyt4540 Рік тому +1

    thank youu so much for this video, very clear explanation and straight to the point . I'm using c++ and learn alot from this tutorial!

    • @PortfolioCourses
      @PortfolioCourses  Рік тому +1

      That’s awesome that you learned a lot from this tutorial, and you’re welcome! :-)

  • @kaigoprod3238
    @kaigoprod3238 2 роки тому +22

    let's recode printf using the original printf function to print the result lmao

    • @allnew301
      @allnew301 2 роки тому +2

      here ive recoded printf but without flags lol hope you find it intersting.

    • @zettai8087
      @zettai8087 Рік тому +2

      @@allnew301 did you make your own printf function? Send a link please

    • @PHXKHEEDGAMING
      @PHXKHEEDGAMING Рік тому +5

      Lmaoooo. This guy has completely missed the point of the entire video. Trynna be funny.

  • @peterolubowale4185
    @peterolubowale4185 Рік тому

    Wow nice video.
    Now we can even attempt to use our own made format specifier, and can now determine the number of variable arguments passed using the count of appearances of '%' instead of using strlen().

    • @PortfolioCourses
      @PortfolioCourses  Рік тому +1

      I'm glad you enjoyed the video! And yes, you could use it to implement functions like printf() with format specifiers and a variable number of arguments. :-)

  • @robssonpeter
    @robssonpeter Рік тому

    My guy I cant thank you enough, this has technically saved my life

    • @PortfolioCourses
      @PortfolioCourses  Рік тому +1

      You’re very welcome Peter, I’m so glad to hear this video was helpful for you! :-)

  • @Shivottmam
    @Shivottmam 6 місяців тому

    Wow 🤩 this is awesome man. Nobody has ever taught me in my academics about creating a fun in C with var num of args. In fact came to know about the H file only through this video and now I because of you know the game. Much Thanks 🙏

  • @safeyamohamed3854
    @safeyamohamed3854 Рік тому

    thank you so much I searched on it for a long time and didn't understand it
    but now I understand it I grateful for you

  • @nwabuezefranklin7676
    @nwabuezefranklin7676 2 роки тому +1

    still the best tutorial on this concept in UA-cam as whole; KUDOS 💪
    Also, i have a question, While practicing this concept I discovered I could not use more than 1 "else if" statement in writing the function. what could cause this?

  • @RahulAnand-p6r
    @RahulAnand-p6r Рік тому

    these videos are really helpful for a beginner like me, thanks❤

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      You're welcome, I'm glad to hear these videos are helping you out! :-)

  • @danieltimileyin3773
    @danieltimileyin3773 Рік тому +1

    I have been following most of your videos and i am a proud student. So far this has been the best tutorial for me on youtube.Then about creating a printf from scratch, how do i go about this?

    • @PortfolioCourses
      @PortfolioCourses  Рік тому +2

      I'm glad you're enjoying the videos Daniel! :-) I don't have a video covering how to make printf() yet. Making a full printf() implementation would actually be a lot of work and get pretty complicated. Online there are tutorials that go over 'smaller' less functional versions of printf() implementations, like this one: www.firmcodes.com/write-printf-function-c/. One day I'd like to do a "build your own printf()" video but it may need to be limited in scope otherwise it may be too long.

    • @danieltimileyin3773
      @danieltimileyin3773 Рік тому

      @@PortfolioCourses thanks for the swift reply

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      You're welcome! :-)

    • @0xRAND0M
      @0xRAND0M Рік тому

      @danieltimileyin3773 Alx maybe?

  • @oscardruke5106
    @oscardruke5106 Рік тому

    Dot g, translated to Spanish, it's "punto g" which happens to be how we named the g spot, so as a bilingual my mind went "that's what she said" automatically after "that's not a dot g".
    Thx for the hard laugh. And also for the tutorial btw

  • @geo-mj4gb
    @geo-mj4gb 10 місяців тому

    Fantastic video but I was almost screaming on the typo you made on stdarg.h. But again, great video.

  • @michaelmusa6489
    @michaelmusa6489 11 місяців тому

    Thank you so much you are my go to guy whenever I don't understand, your videos are very helpful.
    I created my own printf function but im struggling to print strings and characters. Please may you assist me if possible 🙏

  • @gammyhorse
    @gammyhorse 2 роки тому

    One of my favorite videos, this one!

  • @a.v7998
    @a.v7998 6 місяців тому

    Fantastic Video!

  • @evans8245
    @evans8245 Рік тому

    I salute you from the 42 School

  • @massimorusso3894
    @massimorusso3894 Рік тому

    Sono video eccezionali sul Linguaggio C.
    Un saluto dal'Italia.

  • @Chigo-nr8jg
    @Chigo-nr8jg Рік тому

    Think i'll need some time to get this to sink in. Thanks!

    • @PortfolioCourses
      @PortfolioCourses  Рік тому +1

      You're welcome! :-) And yes it's definitely one of those things that takes time to sink in.

  • @cryptotechcoder
    @cryptotechcoder Рік тому

    Just 2 minutes and I'm into it...

  • @hangareducation
    @hangareducation 2 роки тому

    What an excellent explanation

  • @Banikan
    @Banikan 11 місяців тому +1

    is it possible to not specify the number of args?

  • @giuseppefontana5471
    @giuseppefontana5471 11 місяців тому +1

    how to handle struct type with va_args? For example:
    struct mytype{
    char *str;
    int length;
    };
    and a function like this:
    //should compare all struct mytype input and return true, if all inputs have the same size and attribute value, and false if not
    bool equals_mytype(struct mytype arg_i, ...);

  • @auntyemman
    @auntyemman 2 роки тому

    This is without ambiguity, so smooth

  • @geraldinkaba5329
    @geraldinkaba5329 Рік тому

    Thank you very much. I was lost about it. You helped me a lot. I like and subscribe!!!

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      You're welcome, and thank you for subscribing, welcome aboard! :-)

  • @Harrun
    @Harrun 7 місяців тому

    Thank you, this was very helpful.

  • @johneric2720
    @johneric2720 Рік тому

    Your videos are great, love them ❤

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      Awesome, I'm so glad to hear you're enjoying the videos! :-)

  • @sircomplex8629
    @sircomplex8629 Рік тому

    I really like your voice and step by step teaching.

    • @PortfolioCourses
      @PortfolioCourses  Рік тому +1

      Thank you! I'm glad to hear that you enjoy the teaching style. :-)

  • @anitamatthew4409
    @anitamatthew4409 2 роки тому

    Found this very helpful, thank you👍🏾

    • @PortfolioCourses
      @PortfolioCourses  2 роки тому +1

      I'm very glad to hear that Anita, and you're welcome! :-D

  • @mastermax7777
    @mastermax7777 10 місяців тому

    5:40 what happens if you dont put va_end(args)... ? Does it not compile? or leak memory

    • @PortfolioCourses
      @PortfolioCourses  10 місяців тому

      I didn’t know the answer to be honest but this stack overflow answer looks correct: stackoverflow.com/a/587139

  • @amerabuduhair2237
    @amerabuduhair2237 Рік тому

    What is the purpose of for loop when i change from 0 to 3, you didn’t use i, simultaneously va_arg takes the next number while it’s independent of (i)

    • @CheCheDaWaff
      @CheCheDaWaff Рік тому

      The point is to repeat the action the number of times specified by num_args. Not sure how you could do this without a for loop?

  • @2XS
    @2XS 7 місяців тому

    What happened to that good old
    "int main(int argc, char* argv[])"?
    Did "..." replace "char* argv[]" or are both still valid?

    • @SlideRSB
      @SlideRSB 7 місяців тому +3

      argc and argv are different from the stdarg library. You only get to use argc and argv with main(), not with other functions you define.

  • @AmirMovafagh-zn9lc
    @AmirMovafagh-zn9lc Рік тому

    thank you, extraordinary explanation.

  • @fifaham
    @fifaham Рік тому

    This is an idea only: (placeholders, A1, A2, A3, A4...........A1000) I thought this could be one of implementations for voice synthesis, or music ! Where A1, A2 and so on could also take bit wise variables such as amplitude, frequency, filtering, modulation and duration from placeholders: A1 = amplitutde, frequency, filtering, modulation and duration (5 bytes for example) > so A1 could be convoluted with 0x7 + 0xA + 0x3 + 0x01 + 0xC (5 HEX compressed values) and with a rapidly progressing stream of variables and placeholders a decomposed speech can be re-constructed. It is only an idea that could work, or could not work. If there is any designer is in this channel then what do you think of this idea? Could it work? Of course we must have a very high processing speed processor and a very high memory desnsity for this to work properly. Any idea from this audiance?

  • @user-zq7sx9hh6b
    @user-zq7sx9hh6b 3 місяці тому

    So cool, we are try into education project with implementation sprintf function, this video really open my eyes, thanks a lot!

  • @dimitrioskalfakis
    @dimitrioskalfakis Рік тому

    nice presentation.

  • @jackalturk6491
    @jackalturk6491 2 місяці тому

    u used in first example an int value as second argument of start function innsevond example a pointer and both have been worked, i couldnt got it even with four repeats :(

  • @ahmetkarakartal9563
    @ahmetkarakartal9563 Рік тому

    thank you so much

  • @nikhilchitroda9886
    @nikhilchitroda9886 2 роки тому

    To the point, thanks bro 👍

  • @nathanassefa8787
    @nathanassefa8787 Рік тому +1

    Can you please make a video that designs a complete printf function that have its own formatting methond, and it does not use the existed printf function to print datas?

    • @PortfolioCourses
      @PortfolioCourses  Рік тому +1

      I've added this to my list of video ideas Nathan. :-) This would not be a very easy function to build though I don't think, printf() has many options.

    • @nathanassefa8787
      @nathanassefa8787 Рік тому

      @@PortfolioCourses you are right sir that what you already mentioned here is extraordinary. I just asked you to implement printf only using stdiarg since I facing a problem with that. I think many people are struggling too.

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      @@nathanassefa8787 Interesting, I've heard of teachers assigning this problem to students before. It's something I'm going to look into one day, I agree it could make a good video. 🙂

    • @nathanassefa8787
      @nathanassefa8787 Рік тому

      @@PortfolioCourses your way of teaching is really helpful even for beginners. I am looking forward to seeing your complete printf function soon. Thank you sir.

  • @jess-inspired
    @jess-inspired 2 роки тому

    Totally Awesome..

  • @YoussefMorad1
    @YoussefMorad1 Рік тому

    Great !

  • @saklinsk4618
    @saklinsk4618 2 роки тому

    Thank you so much.😊
    .
    ..
    ...

  • @khumbizechimsale
    @khumbizechimsale Рік тому

    I love your videos

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      I'm really glad to hear you enjoy the videos Khumbize, and thank you very much for the positive feedback! :-)

  • @fass.576
    @fass.576 Рік тому

    just wondering why u didn't call the video title Variadic function or even mention the term Variadic , did i get it confused or ......? i loved the video

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      I tried naming the video based on what people search for. I think I should add the term "variadic function" to the description though to help people find it. :-)

  • @the_mellobean
    @the_mellobean Рік тому

    Can I type cast the variable arguments?

  • @warplanner8852
    @warplanner8852 5 місяців тому

    Known or referred to as "variadic arguments".

  • @eduardzemlyanski1719
    @eduardzemlyanski1719 10 місяців тому

    can't process char this way for some reason

  • @its_code
    @its_code Рік тому

    ❤❤❤❤❤

  • @amrgaber4400
    @amrgaber4400 Рік тому

    perfecto

  • @PHXKHEEDGAMING
    @PHXKHEEDGAMING Рік тому

    Currently trying to get va_arg to collect strings parameters. How do we collect string parameters and print?
    This video is all about collecting numbers and no strings. c gets tricky when it has to deal with strings, I’m tired 😪😪

    • @PHXKHEEDGAMING
      @PHXKHEEDGAMING Рік тому

      Is there also a tutorial you mad in pioneers and use cases with many examples? Punters had been messing with me. I’m so frustrated

    • @PHXKHEEDGAMING
      @PHXKHEEDGAMING Рік тому

      Most of the course I’m taking rn uses pointers alll the time 😪.

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      So instead of this:
      int x = va_arg(args, int);
      You would want this:
      char *x = va_args(args, char *)
      if you were passing in some number of strings. :-) When we pass strings to functions what we are really passing is a pointer to a char, the first char in the string.

    • @PortfolioCourses
      @PortfolioCourses  Рік тому +1

      Yes I do have a tutorial on pointers: ua-cam.com/video/2GDiXG5RfNE/v-deo.html. :-) You might find these interesting too:
      ua-cam.com/video/oe2bZKjiWrg/v-deo.html.
      ua-cam.com/video/R0qIYWo8igs/v-deo.html

  • @ghadyyehya9367
    @ghadyyehya9367 10 місяців тому

    thx

  • @jonforhan9196
    @jonforhan9196 Рік тому

    Can you use dark mode i wanna watch this at night without burning my retinas

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      I'm hoping one day that UA-cam adds a feature that can somehow flip videos from a light mode to a dark mode. :-) The research that I did into this came up that it largely comes down to user preference, which has a lot to do with lighting conditions. In low light conditions dark mode can be preferable for many people, where as light mode is often preferred in higher light conditions and is often higher contrast which can be good for users watching a smaller UA-cam video in the corner of a screen while coding along themselves. Unfortunately for now its one of those things where I can't please everybody, but it's something I gave a lot of thought about. :-)

  • @activelow9297
    @activelow9297 8 місяців тому

    Kind of a crummy way of doing it... thank the Lord for variadic templates and variadic functions!

  • @sadelax
    @sadelax Рік тому

    el mejor vídeo que explica las funciones variádicas. gracias!

  • @Antagon666
    @Antagon666 2 роки тому

    That unnecessary if statement in for loop.
    Why wouldn't you just put max=first arg before the for loop ?

    • @PortfolioCourses
      @PortfolioCourses  2 роки тому

      You could do it that way too! There would really need to be a first argument though if you do it that way.

  • @PHXKHEEDGAMING
    @PHXKHEEDGAMING Рік тому

    Can you just make another characters and strings instead of numbers 😪

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      It should look like this:
      void print_all(int num_args, ...) {
      char *next_string;
      va_list ap;
      int i;
      va_start(ap, num_args);
      for(i = 0; i < num_args; i++) {
      next_string = va_arg(ap, char *);
      printf("%s
      ", next_string);
      }
      va_end(ap);
      }
      and then:
      print_all(4, "test 1", "test 2", "test 3", "test 4");

    • @PHXKHEEDGAMING
      @PHXKHEEDGAMING Рік тому

      This works for strings but not for single char. Error was “illegal program” or something illegal, wasn’t even the usual segmentation fault.
      And besides, I have to use putchar() and not printf() since I’m kind of like rebuilding/cloning the printf function

    • @PortfolioCourses
      @PortfolioCourses  Рік тому +1

      For a single char you would have "char" instead of "char *" as the argument to va_arg(). And you would store the value that's returned into a char variable, and then output it with putchar().

    • @PHXKHEEDGAMING
      @PHXKHEEDGAMING Рік тому

      @@PortfolioCourses thanks man

  • @pound9799
    @pound9799 Рік тому

    it doesn't make any sense 😭

  • @sossesam
    @sossesam Рік тому +1

    😂😂alx people full this comment section kai.

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      I don't know what this means. :-)

    • @sossesam
      @sossesam Рік тому +1

      @@PortfolioCourses Sorry, i'm nigerian. came across your video while trying to solve a task given to me in a school am enrolled in. A friend recommended your channel. I noticed a familliar name from the program. i was trying to speak pigdin english

    • @PortfolioCourses
      @PortfolioCourses  Рік тому +2

      @@sossesam Oh I understand now haha, I'm glad that your friend recommended the channel. 🙂 Hello from Canada!

  • @PHXKHEEDGAMING
    @PHXKHEEDGAMING Рік тому

    Lmao this is surprisingly very precise and clear just a little to fast for my brain 🥲. I guess I’ll just keep implementing the rewind button.

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      Thanks! :-)

    • @PHXKHEEDGAMING
      @PHXKHEEDGAMING Рік тому

      @@PortfolioCourses I just tried your logic to apply in a function of summing up the parameters passed.
      To return 0 if number of parameters is 0
      Else go ahead and perform the getting and summing to the parameters.
      It works fine for when the situation of 0 and the situation of correct number of parameters and inputs.
      n = number of parameters
      But now it’s overdoing I just tested the code by inputing n = 8 while passing only 4 other parameters. It’s still worked and started producing very weird numbers.
      How do I tell it to stop or not run if the n is not equal or to the number of parameters passed.
      I hope you understand me 🥺

    • @PortfolioCourses
      @PortfolioCourses  Рік тому

      Hmm, that's weird. argc should be set to the number of parameters, however many. You could "loop through" argv and output each parameter as a string value to help better understand what parameters you are getting. Maybe you're not getting the parameters you think you are, that may help you to debug what's going on. :-)