It\'s common to see a _var variable name in a class field. What does the underscore mean? Is there a reference for all these special naming conventions?
_var
Many people like to have private fields prefixed with an underscore. It is just a naming convention.
C#'s 'official' naming conventions prescribe simple lowercase names (no underscore) for private fields.
I'm not aware of standard conventions for C++, although underscores are very widely used.