C++ is a programming language of many different dialects, similar to the way that each spoken language has many different dialects. In C++, dialects are not because the speakers live in the North or South. Instead, it is because there are many different compilers that support slightly different features. There are several common compilers: in particular, Borland C++, Microsoft C++, and GNU C++. There are also many front-end environments for the different compilers--the most common is Dev-C++ around GNU's G++ compiler. Some, such as G++, are free, while others are not. Please see the compiler listing for more information on how to get a compiler and set it up.

Each of these compilers is slightly different. Each one should support the ANSI/ISO standard C++ functions, but each compiler will also have nonstandard functions (these functions are similar to slang spoken in different parts of a country). Sometimes the use of nonstandard functions will cause problems when you attempt to compile source code (the actual C++ written by a programmer and saved as a text file) with a different compiler. These tutorials use ANSI/ISO standard C++ and should not suffer from this problem (with sufficiently modern compilers). Note that if you are using an older compiler, such as TCLite, you should read check out some compatability issues.

If you don't have a compiler, I strongly suggest that you get one. A simple compiler is sufficient for our use, but make sure that you do get one in order to get the most from these tutorials. The page linked above, compilers, lists compilers by operating system.

C++ is a different breed of programming language. A C++ program begins with a function, a collection of commands that do "something". The function that begins a C++ program is called main; this function is always called when the program first executes. From main, we can also call other functions whether they be written by us or by others. To access a standard function that comes with the compiler, you include a header with the #include directive. What this does is effectively take everything in the header and paste it into your program. Let's look at a working program:

Let's look at the elements of the program. The #include is a "preprocessor" directive that tells the compiler to put code from the header called iostream into our program before actually creating the executable. By including header files, you an gain access to many different functions. For example, the cout function requires iostream. Following the include is the statement, "using namespace std;". This line tells the compiler to use a group of functions that are part of the standard library (std). By including this line at the top of a file, you allow the program to use functions such as cout. The semicolon is part of the syntax of C and C++. It tells the compiler that you're at the end of a command. You will see later that the semicolon is used to end most commands in C++.

The next imporant line is int main(). This line tells the compiler that there is a function named main, and that the function returns an integer, hence int. The "curly braces" ({ and }) signal the beginning and end of functions and other code blocks. If you have programmed in Pascal, you will know them as BEGIN and END. Even if you haven't programmed in Pascal, this is a good way to think about their meaning.

The next line of the program may seem strange. If you have programmed in another language, you might expect that print would be the function used to display text. In C++, however, the cout object is used to display text. It uses the << symbols, known as "insertion operators", to indicate what to output. cout<< results in a function call with the ensuing text as an argument to the function. The quotes tell the compiler that you want to output the literal string as-is. The '\n' sequence is actually treated as a single character that stands for a newline (we'll talk about this later in more detail). It moves the cursor on your screen to the next line. Again, notice the semicolon: it is added onto the end of all, such as function calls, in C++.

The next command is cin.get(). This is another function call: it reads in input and expects the user to hit the return key. Many compiler environments will open a new console window, run the program, and then close the window. This command keeps that window from closing because the program is not done yet because it waits for you to hit enter. Including that line gives you time to see the program run.

Upon reaching the end of main, the closing brace, our program will return the value of 0 (and integer, hence why we told main to return an int) to the operating system. This return value is important as it can be used to tell the OS whether our program succeeded or not. A return value of 0 means success and is returned automatically (but only for main, other functions require you to manually return a value), but if we wanted to return something else, such as 1, we would have to do it with a return statement: