A class is defined in a statement, and it will define its members in a block with multiple statements enclosed by braces {}. As it's a statement, you have to place a semicolon after the last brace. A class can be defined in a header file (as are many of the C++ Standard Library classes), but you have to take steps to ensure that such files are included only once in a source file. Chapter 1, Starting with C++, describes how to do this with #pragma once, conditional compilation, and precompiled header files. There are, however, some rules about specific items in a class that must be defined in a source file, which will be covered later.
If you peruse the C++ Standard Library, you will see that classes contain member functions ...
