Hello, World!
The following is one of the most basic programs that is possible to write in C++. This should give you a first feel of how you can get a computer to do things for you. Be sure to click the Run this code button which will compile and run the code on the server.
You can have fun changing the text into whatever you want.
In order to compile your program, the compiler splits the input into words- similar to how a book is made of words. For a computer program, these words are called tokens. The act of converting your source code into a bunch of tokens is called lexing. Then the compiler arranges tokens into structures that it can make sense of- much like how sentences are composed of words. These structures are referred to as productions.
http://i.imgur.com/BFRnmIr.jpg
In this sample program, we print the contents of one specific token- the string. This is conveniently highlighted as green. The compiler's rules for determining when a token is a string are that it always starts and ends with a double quote. So in order to change the text printed, we simply change the text between the quotes.
This, of course, raises a problem. What if I wanted to print some text with quotes in it?
Exercise: There are at least two separate productions in this program that can be repeated in order to output another string. Can you find at least one of them?