08-03-2009, 12:53 AM

Alright im new to both C and xcode right now, im looking for a bit of help.
Im trying to learn C right now using "the C programming language" book. I am trying to work though the examples, and im still trying to work out the kinks before I really get into it.

when I open a new project and use the standard tool it offers this code for the hello world program

#include <stdio.h>
int main ()
{
    printf("Hello, World!");
	return 0;
}

this works fine and builds with no warnings, however when I try the example in the book im learning from, written by the people who made the language, I get errors during the build

#include <stdio.h>
main ()
{
    printf("Hello, World!");
}

now from a programming point of view I understand what the errors are telling me. My question is why does xcode seems to be using different rules while compiling then what I am expecting to see, and whats in the book?

Also iv noticed both these programs will print if i open them in "console", and it will also run with the same result if I remove the \n, which I definitely cant explain.

08-04-2009, 02:21 PM

Is the warning "warning: return type defaults to 'int'"?

When code or scripts are run from the command line, they are expected to return an 'int' value relating to success or some failure. The compiler seems to be insisting on it. I would consider that a good thing. By the way, I tried using 'void' instead and the compiler warned me I wasn't using an 'int' value.

Perhaps the version of the book isn't up to date on this, has excluded the information for brevity, or the newer compiler is just being helpful. The latest version of that book is 11 years old. A lot has happened in compiler design since then.

As for the '\n'. That is simply a line feed. Removing it will will do no harm here. On the command line the cursor will be at the end of the period if you remove that token. The would mean another print line would start printing at that location.

08-04-2009, 03:28 PM

Originally Posted by xstep

As for the '\n'. That is simply a line feed. Removing it will will do no harm here. On the command line the cursor will be at the end of the period if you remove that token. The would mean another print line would start printing at that location.

Not that this is a bad explanation (it's quite good in fact) but if you're like me, examples help a great deal.

Note that before I show an example, my examples are in Python so ignore the fact that my code looks different. I'm just trying to illustrate what the "\n" does. So, let's say I execute the following command:

print("Hello World!")

Executing that will print Hello World! to the screen. Now, if I change this code to include "\n", the output will put what I include after it on a new line. So, if I execute the following:

print("Hello\nWorld!")

the output looks like this:
Hello
World!

Hope that helps.

08-07-2009, 10:23 PM

Thread closed due to high spammer activity.

Please continue discussion in PM.