3. Languages

In this section, we do not intend to offer an introduction to each of the languages mentioned, but only to show how the general principles are implemented in each of them – and, in particular, what terminology is used to designate the various system components. As a result, we have refrained from giving any indication of syntax and, consequently, from giving examples. Languages officially recognized as "object-based" can be divided into two groups: those in which all data has the status of an object, and those which have been designed as extensions to classic procedural languages, and which therefore offer the possibility of combining the use of objects with traditional programming in the base language. We'll deal first with languages in the first group, starting with SMALLTALK, as it is the simplest and closest to the theoretical model sketched above, followed by EIFFEL, which differs in...