(Note: This set of notes was compiled from several separate documents, and points may be repeated.)

Contrast between imperative languages (C, Pascal) and object-oriented languages.
Key concepts and terminology for object-oriented languages.

Analogous to types for imperative languages, and the key organizational feature of object-oriented languages.

The following table shows the correspondence between features of C and of object-oriented languages.

There are two or three other significant aspects to object-orientation. The first is "hierarchy" or "inheritance"; the second is "protection".

Object-oriented programming is distinguished by having
- explicit visibility (of variables and functions) controlled through thedeclarations of types and variables, rather than through nesting of functions.
- inheritance
- override.
C++ is not a pure object-oriented programming language, but rather adds object-oriented features to ANSI C.
- In particular, almost any legal C program will be a legal C++ program, if not in the spirit of object-oriented programming.
However, system interfaces may be different. The built-in functions, and their organization into #include files, the effect of other #-commands, and of other system utilities, may differ.
Explicit memory management is handled either by object-oriented features (see constructors and destructors below), or by the new and delete commands (rather than malloc, dealloc, and company.
Most of the object-orientation shows up in C++ in constructs and use of structured variables.

Some other ideas: abstract classes (base classes with no instances themselves); virtual functions (which allows a certain degree of polymorphism by allowing derived classes implicitly in prototypes.
Files in C++.
Management of large files: makefiles and projects .