"strictly a class operation" means
Answers
Answer:
A design class represents an abstraction of one or several classes in the system's implementation; exactly what it corresponds to depends on the implementation language. For example, in an object-oriented language such as C++, a class can correspond to a plain class. Or in Ada, a class can correspond to a tagged type defined in the visible part of a package.
Classes define objects, which in turn realize (implement) the use cases. A class originates from the requirements the use-case realizations make on the objects needed in the system, as well as from any previously developed object model.
Whether or not a class is good depends heavily on the implementation environment. The proper size of the class and its objects depends on the programming language, for example. What is considered right when using Ada might be wrong when using Smalltalk. Classes should map to a particular phenomenon in the implementation language, and the classes should be structured so that the mapping results in good code.
Even though the peculiarities of the implementation language influence the design model, you must keep the class structure easy to understand and modify. You should design as if you had classes and encapsulation even if the implementation language does not support this.