OOP illustrations from Microsoft Visual FoxPro 6.0: Programmer’s Guide

Microsoft Press’s Microsoft Visual FoxPro 6.0: Programmer’s Guide1998 illustrates concepts of object-oriented programming with phones.

An old-fashioned rotary-dial phone next to its schematic.

A rotary-dial phone with half of its front removed revealing the electronics inside.

A rotary-dial phone at the top with lines leading to five different phones at the bottom: another rotary-dial phone, push-button phone, cell phone, fax, payphone.

Phones with dials on the left become identical phones with buttons on the right.

Contents

Class/object

Encapsulation

Subclassing

Inheritance