The #include statement tells the C++ preprocessor to insert the
definitions
of variables, classes, and functions into the current
file. #include <iostream.h>, for example, lets you use the cout and
cin functions, and
#include <math.h> lets you use extra functions
like the square root function sqrt(). To #include files that are not
standard with C++ (files you define yourself, for instance) you use quotation
marks instead of angle brackets. E.g.: #include "my_file.h"
Commenting is important for documenting your code. Not only will it make
your code much easier for other people to understand, but it will help to remind
yourself what you were thinking if you look back at your code at a later time.
Whitespace is the composition of spaces, tabs, and newlines that the compiler
ignores when compiling your code. This means that you can use indentation and
line spacing to make your code more readable.
