Thank you sir. Adding you to my favorites. I think I'm going to watch all your videos in C. Hope you have C++ as well. I remember nothing from my introduction to C class almost two years ago...so you might prove to be a life saver line for me.
@@maryannemuthoni5388 What's the last cohort? I just deffered to c21 myself. Actually I only found your comment because I'll be going through the materials for c. I finished shell but I'm not very confident in my c yet so i didn't think going forward was wise.
I learned C with a awesome book The C programming Language by K&R. The book is dated and the examples have bugs in them but it's only two hundred pages, and it gets you up to speed quick, the first chapter you will know how to do if's, whiles, for's and trust me you'll have a great understanding of the language. If you are stressed out about the information not "sticking" the book will make it stick. This is for everyone who wants to learn the best way; the hard way. Also, the world has progressed passed C, you won't get a job programming it instead you'll get the fundamentals you need to know to learn OOP languages, so syntax, specific nit-picks of functions in the book don't really matter. You probably should be using it to get a marketable language. Also, my suggestion is to use linux, use GCC as a compiler and the linux terminal to compile and run. I've always had trouble keeping the window up with EOF references and other problems that are prone to IDE's. Nothing is more annoying then having an error because of the software of the IDE or the OS. If you want a hassle free way to code, just type the commands, it's not hard because the terminal by pressing up will copy the code automatically.
I made it to about 8:25 and I'm kind of lost rn, I don't quite understand. what is taking up 1-4 bytes, where is it stored? why does it take up 1 byte? what is the use of a byte? ive never had any programming experience in the past so this just confused me
sir i tried doing the same in the terminal but in says E248 no string under cursor when i try to type #shrap ??? googled alot but still no solution....
cant even get passed the first step. I type vi hello.c. creates the vertical ~'s then when I try to type in "#include , all I get is a red error "No string under cursor". please help
***** .. OMG OMG OMG AXAXAXAXAXAXAXAXAXAXAXAXAXAX LAUGHED SO HARD CRIED SO MUCH YOURE SOSOSOSOOS AWESOMEA ABSOLUTELY RARE OMG KIND HEARTED LOVELY GREAT AMAZING CREATURE I LOVE YOU I LIKE YOU I LIKE YOUR STYLE BE SAFE OMG AXAXAXAXAXXAXAXAXAX MY HEART IOMGGGGG I WANNA BE YOUR FRIEND I WANNA HUG YOU LUCKY YOUR FRIENDS AND FAMILY THAT THEY HAVE YOUUU
i need some help and fast: i need to learn to program and to make a program for recognising capacitors but other than your videos i don't know much about it, for example: i need to know how to make 2p to be = to 2 pikofarads, or how to make the first colour chosen to have the value of 3 ? any help is apriciated
hello man can you help me ? i know gow to PRINT ancii chars on screen.. what i need to know its how to execute those commands .. (example: i want to extract ancii chars + concaternate then + execute then) char a = 21; char b = 32; char command = putchar(a);putchar(b); int system(char command); system(command);
Okay so I have VirtualBox and I downloaded Ubuntu in the ISO format, I made a VM with Ubuntu and all that comes up is a black screen after the VM is created. So my question is, whats this white screen he calls Vi? I know it is Unix based, where do I get it or how do I get to the same screen he is on? Somewhat confusing just starting out...
I don't get why we should use int for main and the void argument and return 0, i heard what they do but i don't get why are they necessary ? I compiled the program without them and it worked perfectly fine .
Since it's incorrect, it will form a habit that's why. Some compilers will produce an error, whereas some won't. It is kind of frowned upon in the programming community because they fear that if it's printed in books, and taught by professors then this bad habit will spread
depends on what OS you are running. In Windows look up Visual Studios Express Editions. In Mac I think XCode (but clang is available as well because of the BSD userland), and on Linux GCC.
this function only print the string into output (monitor) and not returning any value (to catch). in other word it returns zero, zero is an integer. thats why...
I am pretty sure I don't know what i'm doing 100%. But gcc says that you need a ; before the return. So what I did was ;return(0); and it worked. But are both semi colons necessary?
there was probably another line before the return that you forgot a ; on. Because you put it there, it attributed that semicolon to the line that was missing one, even though it looks wrong. That's because spaces and enters in C for the most part are purely visual, the machine reads it linearly.
Iv only coded in java so it could be different but couldnt you just create the return type on the main the method void. Then you could just print "Hello World" and not have to return anything.
Yes you can do a void method. However, it is best to use the int, because on linux shells, most of them will have an error check. If your main method was to run properly, it would return a 0, if it failed, it would return anything that you specified. For example if you made a loop, and if the loop failed you can say "return 1" This way, if the program failed, linux shell will tell you it received a 1, telling you specifically where your bug is.
I understand that you would do that in an instance with a for loop. I was just stating it would be more effective to use the void method in that instance.
***** in THAT instance of course. but NEVER use a void method in the main when you are making a REAL application or software. it is just horrible practice.
***** Don't listen to these folks. The only standard (guaranteed to exist) entry points return int; There are no others guaranteed to exist in the standard. int main(void) and int main(int argc, char **argv) are the two common standardised ones. If you use anything else, don't be surprised if some compilers spew warnings/errors at you, or if your code crashes in mysterious ways on some computers.
+Mitchel Austin If u haven't figured it out yet, u use CD command to go to different folders. For example: CD examples if ure at the correct place. Or else u need to CD to the place where u created the examples folder. Just create a folder named examples whereever u want ;)
I have no clue what's going on. Can someone direct me to a more basic video. I want to get into programming but don't know where to start. All I know about programming is that somebody somewhere types some codes and makes the internet work.
So I have taken an intro to Java class and now in the middle of the next level up as well as a class that deals with C. You would probably do better getting your feet wet in Java or Python- both higher-level languages that are more intuitive than C which is, like he said, dealing with the hardware more directly. If you look at the free online courses that MIT provides, they show you how to get Python running on your personal computer, for example. I also know khanacademy does some work with python as well, and it would be better to learn from him than right on the MIT website, because they go pretty fast.
am having A BAD TIME learning C programming..pls what should i do so as to be Best in it....Its giving serious night mare,its a compulsory course in mx school..pls talk to me somebody THANKS
Hello. I am starting self paced learning of C just from TH-cam videos, like yours.. And right from the beginning I am not getting few things here: No1: why I need to include :"int main" statement and then "return 0"...where I am actually telling the machine returning the integer 0. Seems like the first statement is not needed, then. What if I say "return 1.20"??? Would it return Integer(and if so, which one?) or Real-the one I commanded...i.e. 1.2???. No2: I would assume, that after printing statement "Hello, learner" the machine will actually print out the 0 (which I commanded with statement "return 0'). But no such thing has happened...which would lead me to think, that something went wrong with my program....And if the machine doesn't actually display the 0 (even if I command it), then why to command it at all??? What good does it do for me, if I cannot visually confirm, that it actually returned the 0...?
1. Excluding ‘int’ should yield a warning upon compiling. It should be included so the compiler knows what to expect. ‘return 0’ is a bit ambiguous in that ‘0’ could be interpreted as an int or a char. The compiler can’t know for sure so the programmer should specify. 2. Note that print is not the same as return. Print outputs its arguments to system out. Return outputs its arguments to whatever is there to catch it. In this example return outputs its arguments as an exit status. The exit status is a way to communicate with whatever called the program. It becomes necessary when there are programs that depend on eachother. 3. Unix users can check exit status with ‘echo $?’. For other operating systems, Google is your friend. 4. I don’t know, what happens if you say ‘return 1.2’?
+Jiri Tichy The 0 returned is not displayed but is used as a status value by the calling program, which is Windows or Linux, since that is where the call to your Hello Learner program came from. The thing to note is that it is usually a status or can be a processed value. A zero usually means everything ok. A non zero value usually means a problem and it is up to the calling program what to do next. In this case, whatever the status or value returned was, there was nothing further to to except return to the OS and the C editor program.
i could download Qbasic and put up some video tutorials to help. For my freshman year in highschool i developed a graphic based 2d rpg game in qbasic which is very complex lol. but i can show you guys how to do it and you will learn some of the most core functions of every programming language
Yes it works perfectly fine just you need to download codeblocks and GCC will be in the bin file . So you can add that to path et voila it will work fine.
A better/more user-friendly terminal editor is nano. There's always been the nano side and the vi side but nano is my preference. Ex. touch hello.c (touch is the "create this document" command) nano hello.c (edits the document named "hello.c" in your current working directory) You don't have to do the touch command because nano will create the document if it does not exist but it's always good to know more commands. When done editing press Ctrl+X and save document to name.
Jonah St-François Nano is much easier to use, but Vim is much better IMO. The controls take longer to learn in Vim, but it's all around better, That being said, Nano isn't bad.
Grimmwood It's a personal preference more than anything at this point. I'm much more comfortable in nano than I have/will ever be in Vi so nano is a better tool for me.
Jonathan covered that in the video, but that was confusing for me at first. The '.h' just stands for header. Stdio is known as a preprocessor directive, and it means standard input and output. So when you are programming and you initially write #include stdio.h - you are essentially telling the compiler to recognize something from that header - like the printf(), or scanf(). See en.wikipedia.org/wiki/C_file_input/output for more information on stdio headfiles. You could also use a math.h preprocessor directive if you want to utilize the sin, cos, sqrt (square root) functions in the complier. So it is very important to use the right header when programming so that it means something to the compiler. Hope that helps.
This single tutorial covered 3 entire chapters of my C programming book in 11 min. This is definitely not a basic tutorial
Thank you sir. Adding you to my favorites. I think I'm going to watch all your videos in C. Hope you have C++ as well. I remember nothing from my introduction to C class almost two years ago...so you might prove to be a life saver line for me.
how are you now at your life
@@theprogrammer5200wow ...
best c programing tutorial in world, many complete useless tutorial in youtube, edx, udacity, coursera, udemy.
thank you very much Jonathan.. because last two months i studied nothing in c... by watching this video a idea came for me.. this is nic
Here from the ALX software engineering program and this video has taught me so much.
Sasa Mary! #dohardthings 💪how's it going so far?
@@FlameBelliedWalrus I am so behind I am considering quitting and I am in the last cohort so I can't defer 😭
@@maryannemuthoni5388 What's the last cohort? I just deffered to c21 myself. Actually I only found your comment because I'll be going through the materials for c. I finished shell but I'm not very confident in my c yet so i didn't think going forward was wise.
Thank you for putting this out there, i am doing a bootcamp in a few months and i know they cover C and i am very new to it, but i can pick it up.
Informative.Thanks for sharing to us
Finally a programming tutorial I can understand!
If alx brought you here, signify 😂
😂
It's great to be able to finally understand someone.
Finally, some free C programming tutorials
Your voice makes the class understandable, great communication skill you got sir 👌
I learned C with a awesome book The C programming Language by K&R. The book is dated and the examples have bugs in them but it's only two hundred pages, and it gets you up to speed quick, the first chapter you will know how to do if's, whiles, for's and trust me you'll have a great understanding of the language. If you are stressed out about the information not "sticking" the book will make it stick. This is for everyone who wants to learn the best way; the hard way.
Also, the world has progressed passed C, you won't get a job programming it instead you'll get the fundamentals you need to know to learn OOP languages, so syntax, specific nit-picks of functions in the book don't really matter. You probably should be using it to get a marketable language.
Also, my suggestion is to use linux, use GCC as a compiler and the linux terminal to compile and run. I've always had trouble keeping the window up with EOF references and other problems that are prone to IDE's. Nothing is more annoying then having an error because of the software of the IDE or the OS. If you want a hassle free way to code, just type the commands, it's not hard because the terminal by pressing up will copy the code automatically.
Your are right The best way to learn is the hard way!
Please can you help me with the pdf of the book?
Please can you help me with the pdf of the book?
may i get the pdf please
please send us the pdf
nyc video very helpful for the beginners
U r awesome the language way how u teach its educational no one teach like u superb
#include
#include
Void main()
{
Int love=0;
While(love
Thanxx every one for liking comments
***** lol
*****
System.out.println("c#=java");
***** where do you live bro ?
***** yes bro I am from India .....you are studying ??? which std
I like this site for sequencial learning.
Wow, I really enjoyed this session
Finally a guy who doesnt have an Indian accent
Layth Abdulwahab lmfao
:)))
bro I swear
thank the LORD ! lol
lol
this actually is kind of an issue. I grew up with my best friend Sitanj and Anish and never thought this way until I started taking CS and EE classes.
personally i learned q basic first, then visual basic, then i moved on to C. in my opinion this is a very good way to start.
I made it to about 8:25 and I'm kind of lost rn, I don't quite understand. what is taking up 1-4 bytes, where is it stored? why does it take up 1 byte? what is the use of a byte? ive never had any programming experience in the past so this just confused me
Thanks, this is really explanatory
from ALX_SE say Hi
i downloaded visual studio and changed the theme to make me look like some l33t hakcer programmer wizard, other than that i dont have a clue
WolvesFanVideos really depends on what varant of Visual Studio you have.
Visual Studio Code = text editor
Visual Studio 20XX (style) = IDE
Oh, but that video is actually very good! Thank you for helping me through the path of learning!
sir i tried doing the same in the terminal but in says E248 no string under cursor when i try to type #shrap ???
googled alot but still no solution....
Best explanation.
cant even get passed the first step. I type vi hello.c. creates the vertical ~'s then when I try to type in "#include , all I get is a red error "No string under cursor". please help
make sure to enable hardware virtualization with windows through the bios, virtualbox wouldn't run Ubuntu until I did that.
Really fascinating. I liked the shell tricks.
I want to know what is the software that I have to download for c language?
Thanks for posting. Very helpful
This is very useful after 9 years. Thank you so much
thanks for making this video couldn't find a good one for a long time!
I still have no idea what's going on....
hahahhahahahahahah join the cub
***** .. OMG OMG OMG AXAXAXAXAXAXAXAXAXAXAXAXAXAX LAUGHED SO HARD CRIED SO MUCH YOURE SOSOSOSOOS AWESOMEA ABSOLUTELY RARE OMG KIND HEARTED LOVELY GREAT AMAZING CREATURE I LOVE YOU I LIKE YOU I LIKE YOUR STYLE BE SAFE OMG AXAXAXAXAXXAXAXAXAX MY HEART IOMGGGGG I WANNA BE YOUR FRIEND I WANNA HUG YOU LUCKY YOUR FRIENDS AND FAMILY THAT THEY HAVE YOUUU
***** Greece! And it's not a compliment!, it doesn't hide winning something or taking advantage from something, it@s the truth!
@@languagelover9170 ti pineis?
@@Discordxeroxero6454 How do I join?
Thank you so much for this amazing video Jonathan! You're a Genius!!!
Thank you, still got no idea how rough the road i will be choosing.
You are a great teacher ! Thanks for this valuable tutorials....!
th-cam.com/video/Kfv1Taj45Tg/w-d-xo.html
is there such thing as a 'double float'?
Thank you for your simple explanation.
How do you get the virtual box to recognize vi
i need some help and fast:
i need to learn to program and to make a program for recognising capacitors
but other than your videos i don't know much about it, for example:
i need to know how to make 2p to be = to 2 pikofarads, or how to make the first colour chosen to have the value of 3 ?
any help is apriciated
What's a good C/C++ compiler/computer I can install onto my desktop to actually code in C/C++?
Kyle DuBois Visual Studio
Are you familiar with Code Blocks because that's what I've been using.
What's something that I can use to code multiple languages in?
you are great man,,,,,,,,i like your posts,,,,,,,really awesome
hello man can you help me ?
i know gow to PRINT ancii chars on screen..
what i need to know its how to execute those commands ..
(example: i want to extract ancii chars + concaternate then + execute then)
char a = 21;
char b = 32;
char command = putchar(a);putchar(b);
int system(char command);
system(command);
excellent video. very interactive and good job.
How did you made your Ubuntu installation to look this way?
all the languages are the same. glad there are patterns to recognize.
I know all the syntax for must languages , but even that I can't write code and I don't know how to start , any help .. Thanks
Just start, it's as simple as that..
Thank you sir ... very Helpful......
Also if you would be able to add download links for the progamms used in the vid
Hello Mr. jonathan is that the 9th part of your tutoriall was last one or we could learn more
good job
and many thanks
Thank you for your great efforts ...
how can we implement bitmap indexing in c programming?
Your video is excellent. I love it.
Okay so I have VirtualBox and I downloaded Ubuntu in the ISO format, I made a VM with Ubuntu and all that comes up is a black screen after the VM is created. So my question is, whats this white screen he calls Vi? I know it is Unix based, where do I get it or how do I get to the same screen he is on? Somewhat confusing just starting out...
Please can you throw more light on modifiers
how do we edit the stdio.h library? why didn't you showed what was in the library and explain that??
"stdio.h" is a header file, a libarary in C topic is another thing.
probably you know this after 10 years, but anyway ...
very good tutorial thanks
so basically include is import?
I don't get why we should use int for main and the void argument and return 0, i heard what they do but i don't get why are they necessary ?
I compiled the program without them and it worked perfectly fine .
Since it's incorrect, it will form a habit that's why. Some compilers will produce an error, whereas some won't.
It is kind of frowned upon in the programming community because they fear that if it's printed in books, and taught by professors then this bad habit will spread
returning anything from main is optional, but a good practice.
best ever in youtube
So interesting
sir,
good evening i want one help
code program to display crocketscore board in devc++
What's the best compiler to use?
I think vim is best !
depends on what OS you are running. In Windows look up Visual Studios Express Editions. In Mac I think XCode (but clang is available as well because of the BSD userland), and on Linux GCC.
Yonghong Niu Vim is good, but it is technically just a text editor.
What software is this and is it free like python?
hello jonathan where can I download a compiler in C using windows 8 OS I hope you help me thank you :)
You could try TCC (Tiny C Complier), but there are hardly any C compliers for later versions of Windows. You could always use an online complier.
6:30 *Why* did we say the hello world main method should return an integer? You should explain things more in depth.
this function only print the string into output (monitor) and not returning any value (to catch). in other word it returns zero, zero is an integer. thats why...
ok now where we can download this?
Anywhere can I find the slides?
Hey is it ok if i use Notepad++ for the helloworld?
Nice work Prof. Engelsma
I am trying to use C to write a program that will play my online game for me can someone help?
I am pretty sure I don't know what i'm doing 100%. But gcc says that you need a ; before the return. So what I did was ;return(0); and it worked. But are both semi colons necessary?
there was probably another line before the return that you forgot a ; on. Because you put it there, it attributed that semicolon to the line that was missing one, even though it looks wrong. That's because spaces and enters in C for the most part are purely visual, the machine reads it linearly.
Nice tutorial
Iv only coded in java so it could be different but couldnt you just create the return type on the main the method void. Then you could just print "Hello World" and not have to return anything.
Yes you can do a void method. However, it is best to use the int, because on linux shells, most of them will have an error check. If your main method was to run properly, it would return a 0, if it failed, it would return anything that you specified. For example if you made a loop, and if the loop failed you can say "return 1" This way, if the program failed, linux shell will tell you it received a 1, telling you specifically where your bug is.
I understand that you would do that in an instance with a for loop. I was just stating it would be more effective to use the void method in that instance.
***** in THAT instance of course. but NEVER use a void method in the main when you are making a REAL application or software. it is just horrible practice.
Alright thanks!
***** Don't listen to these folks. The only standard (guaranteed to exist) entry points return int; There are no others guaranteed to exist in the standard. int main(void) and int main(int argc, char **argv) are the two common standardised ones. If you use anything else, don't be surprised if some compilers spew warnings/errors at you, or if your code crashes in mysterious ways on some computers.
Eclipse or Visual Studio which one should i use? I'm beginner.
+TheGreatHektor I prefer Visual Studio 2015
+TheGreatHektor Dev C++
you explain so well,.. !
how do i get vi to work in the ~examples folder? can anyone explain?
+Mitchel Austin If u haven't figured it out yet, u use CD command to go to different folders.
For example: CD examples if ure at the correct place. Or else u need to CD to the place where u created the examples folder.
Just create a folder named examples whereever u want ;)
Thanks mate! I did figure it out a while ago, but still, thanks for helping :).
Help! My first single quote(apostrophe) appears backward when I run my program! This is holding up my progress. Anyone???
great
thinks.
things are going well!
people need little leaning program
do i need other knowledge to learn c? or what Kind of knowledge would help? i never had computing lessons and i feel like im thrown into cold water.
I have no clue what's going on. Can someone direct me to a more basic video. I want to get into programming but don't know where to start. All I know about programming is that somebody somewhere types some codes and makes the internet work.
So I have taken an intro to Java class and now in the middle of the next level up as well as a class that deals with C. You would probably do better getting your feet wet in Java or Python- both higher-level languages that are more intuitive than C which is, like he said, dealing with the hardware more directly. If you look at the free online courses that MIT provides, they show you how to get Python running on your personal computer, for example. I also know khanacademy does some work with python as well, and it would be better to learn from him than right on the MIT website, because they go pretty fast.
I would recommend to look up some videos about BASIC
^^ horrible advice. python maybe.
JAVA made me quit coding twice DON'T MAKE THE MISTAKE I DID.
It’s not for everyone, but if you are really interested look up hello world and start there. Eventually you will figure it out. Don’t give up :)
am having A BAD TIME learning C programming..pls what should i do so as to be Best in it....Its giving serious night mare,its a compulsory course in mx school..pls talk to me somebody THANKS
good lessons
Thanks this is good edumacation
Great lesson! Thanks for putting it out here for us to see
What is the book called? I may like to read it.
Never mind.
Hello. I am starting self paced learning of C just from TH-cam videos, like yours.. And right from the beginning I am not getting few things here:
No1: why I need to include :"int main" statement and then "return 0"...where I am actually telling the machine returning the integer 0. Seems like the first statement is not needed, then. What if I say "return 1.20"??? Would it return Integer(and if so, which one?) or Real-the one I commanded...i.e. 1.2???.
No2: I would assume, that after printing statement "Hello, learner" the machine will actually print out the 0 (which I commanded with statement "return 0'). But no such thing has happened...which would lead me to think, that something went wrong with my program....And if the machine doesn't actually display the 0 (even if I command it), then why to command it at all??? What good does it do for me, if I cannot visually confirm, that it actually returned the 0...?
1.
Excluding ‘int’ should yield a warning upon
compiling. It should be included so the compiler knows what to expect. ‘return
0’ is a bit ambiguous in that ‘0’ could be interpreted as an int or a char. The
compiler can’t know for sure so the programmer should specify.
2.
Note that print is not the same as return. Print
outputs its arguments to system out. Return outputs its arguments to whatever
is there to catch it. In this example return outputs its arguments as an exit
status. The exit status is a way to communicate with whatever called the
program. It becomes necessary when there are programs that depend on eachother.
3.
Unix users can check exit status with ‘echo $?’.
For other operating systems, Google is your friend.
4.
I don’t know, what happens if you say ‘return
1.2’?
+Jiri Tichy The 0 returned is not displayed but is used as a status value by the calling program, which is Windows or Linux, since that is where the call to your Hello Learner program came from. The thing to note is that it is usually a status or can be a processed value. A zero usually means everything ok. A non zero value usually means a problem and it is up to the calling program what to do next. In this case, whatever the status or value returned was, there was nothing further to to except return to the OS and the C editor program.
+has King
i could download Qbasic and put up some video tutorials to help. For my freshman year in highschool i developed a graphic based 2d rpg game in qbasic which is very complex lol. but i can show you guys how to do it and you will learn some of the most core functions of every programming language
In depth info. available on cymposium
Will this work Inn window s and how
Yes it works perfectly fine just you need to download codeblocks and GCC will be in the bin file . So you can add that to path et voila it will work fine.
Can u plz take a video on elements of programming in practice
A better/more user-friendly terminal editor is nano. There's always been the nano side and the vi side but nano is my preference.
Ex.
touch hello.c (touch is the "create this document" command)
nano hello.c (edits the document named "hello.c" in your current working directory)
You don't have to do the touch command because nano will create the document if it does not exist but it's always good to know more commands.
When done editing press Ctrl+X and save document to name.
Jonah St-François
Nano is much easier to use, but Vim is much better IMO.
The controls take longer to learn in Vim, but it's all around better,
That being said, Nano isn't bad.
Grimmwood It's a personal preference more than anything at this point. I'm much more comfortable in nano than I have/will ever be in Vi so nano is a better tool for me.
I'm at 4:21 and I don't understand a word :(
nobody does.. give it some time...
then start with the PYTHON !!!
Brilliant
ive installed virtual box on my windows and downloaded the ubuntu .. then what next
+bobkorg engineer Don't do that, its way too much to do. Just install Dev C++ on Windows and start writing your code.
What does ".h" do to the stdio?
header
Jonathan covered that in the video, but that was confusing for me at first. The '.h' just stands for header. Stdio is known as a preprocessor directive, and it means standard input and output. So when you are programming and you initially write #include stdio.h - you are essentially telling the compiler to recognize something from that header - like the printf(), or scanf(). See en.wikipedia.org/wiki/C_file_input/output for more information on stdio headfiles. You could also use a math.h preprocessor directive if you want to utilize the sin, cos, sqrt (square root) functions in the complier. So it is very important to use the right header when programming so that it means something to the compiler. Hope that helps.