Design Techniques

Question 1

Design Technique: Documentation

Answer 1

Main focus on readability:

• code documentation and comments
• code style conventions and restrictions of language features
• good naming of identifiers

Question 2

What are API comments?

Answer 2

comments on class level and method level

• add useful information for developers
• > describe in detail when method is called, its behaviour (side effects, exceptions, etc), additional restrictions

Question 3

What are Statement level comments?

Answer 3

Describe implementation details for own code

Question 4

Design Technique: Refactoring

Answer 4

technique for restriction an existing body of code without changing its external behaviour

• preparing addition of features
• improving design (eg. cohesion) and maintainability
• increase comprehensibility

Question 5

Refactoring Technique: Extract Method

When?

Answer 5

• one method does many things

- code duplication within the method itself or across several methods

Question 6

Refactoring Technique: Extract Method

Worauf achten?

Answer 6

Variables:
- ensure that they are only used in the extracted
code
-> declare them locally
- exactly one variable is modified in code
-> check if it can become the return value
- more than one var is modified
-> method not applicable

Question 7

Refactoring Technique: Move Method

When?

Answer 7

Class has too many responsibilities

-> split them into different classes (SRP)

Question 8

Refactoring Technique: Move Method

Check

Answer 8

Does the source method

• use features of the source class
• override method or is overriden

Question 9

Refactoring Technique: Extract class

When?

Answer 9

if class has two or more independent responsibilities and no other class is suitable for the fields and methods