Hoofdstuk 11 - Refactoring

Question 1

Can you explain how refactoring differs from plain coding?

Answer 1

Changes the software system in such a way that it does not alter the external behaviour of the code, yet improves its internal structure.

Question 2

Can you tell the difference between Corrective, Adaptive and Perfective maintenance? And how about preventive maintenance?

Answer 2

Corrective fixing errors, Adaptive to new environments and Perfective with new functionality. Preventive maintenance by refactoring, it is a new category.

Question 3

Can you name the three phases of the iterative development life-cycle? Which of the three does refactoring support the best? Why do you say so?

Answer 3

Prototyping, expansion, consolidation. Consolidation supports this the best, as refactoring during expansion slows down the productivity.

Question 4

Can you give 4 symptoms for code that can be “cured” via refactoring?

Answer 4

Duplicate code, nested conditionals, large classes/methods and abusive inheritance.

Question 5

Which 4 activities should be supported by tools when refactoring?

Answer 5

◦ rapid edit-compile-run cycles
◦ reverse engineering facilities
◦ regression testing
◦ version & configuration management.

Question 6

Why can’t we apply a “push up” to a method “x()” which accesses an attribute in the class the method is defined upon (see Refactoring Sequence on page 27–31)?

Answer 6

Because we need to “push up” the attribute too.