Great resources for beginning C programming

To start out, lets create the simple "Hello World" example:

1: #include
2:
3: int main()
4: {
5: std::cout << "Hello World!" << std::endl;
6: return 0;
7: }

Breakdown:

Line 1: #include
#include will include a C++ library - in this case the iostream library
The iostream library is used to "get" and "send" streams of data - usually text strings.

Line 3: int main()
"int" is a desription of what type of value, the function will return.
main() is the function that will be called as the first thing, when the program is run.

Line 4: {
This marks the start of a block of code...
In this case, it starts the content of the main() function.

Line 5: std::cout << "Hello World!" << std::endl;
First of: cout is a way of printing something to the standard output - i.e. your shell.
endl is the same as this: "\n"
A newline character.

std:: is refering to would is called the standard namespace...
Namespaces is used in C++ to create distinct areas for you classes, functions, etc.
An example: std::my_function() is completely different from myns::my_function().

Don't worry about this at first...
To make things easier, you could remove the std:: declarations from line 5 and add this to line 2: using namespace std;
So that these lines looks like this:

2: using namespace std;
...
5: cout << "Hello World!" << endl;

Line 6: return 0;
Remember that line 6 created the function main, that will return an int (integer or a positive number)?
Well this is where we actually return an integer... in this case 0, which means everything went alright.

Line 7: closes the block of code defined as the function main()

That's it! Really! ;-)

Save the code in a file called helloworld.cpp - or what ever you like, as long as you remember to use .cpp as the extension.

Compilation... Well... There is so many options, when it comes to choice of a C++ compiler...
Mostly it depends on operating system... I will NOT get into C++ development specific to the Windows platform, as I am only used to UNIX like operating systems (yes that includes the Mac)...

Well the most popular compiler on Linux / BSD platforms are the gnu c++ compiler.

You can check if you have it, by running this command in your shell:
g++ -v

This should tell you all kinds of things, but look for a line similar to this:
gcc version 4.0.1

This tells you that the compiler is installed, and what version is installed.

If you haven't got the compiler... get it... on debian linux you can run the following command:
sudo apt-get install g++
assuming you have root access, that is...

Well... to the actual compilation...
Run this command in your shell:
g++ helloworld.cpp -o helloworld
This will create a program called helloworld, as this is what you asked for (-o helloworld)

Now run the program with:
./helloworld
And you should see this:
Hello World!

Well... This is it for now!

Leave a comment, if you have any questions!

I hope you learned something and enjoyed the site!

Best regards
Dan Larsen