Question

1. From the statement “Lincoln is the 16th US president”, we can come up with the following designs. Which one is most appropriate?

a. Two independent Classes: Lincon and President.

b. Two Classes: Lincon and President, with Lincon subclass of President.

c. A class President, with Lincon being an object of the class President.

d. None of the above.

4.An advantage of inheritance is that

a. All methods in a super class can be inherited by its subclasses.

b. All instance variables in a super class can be accessed by subclasses.

c. An object of a subclass can be treated as an object of the superclass.

d. None of the above.

6. Pair programming refers to the style where two programmers switching their roles in coding and real-time reviewing. This encourages:

a. Collective code ownership

b. Cross-learning among peers

c. Code critics and refinement

d. All of the above

Answer 1

1. Choice(c) is correct, ie, A class President, with Lincon being an object of the class President.

• President being a position and lincon can just hold that position for some years. So, a class is sort of having a home and each family member can be considered as its object. So this implies with president position as well. Each new president can be the object of that class. Creating a class with name as 'lincon' will lead to confusing code management.

2. Choice(c) is correct, ie., An object of a subclass can be treated as an object of the superclass.

• Option-a is false because constructor is a method(in superclass) and it cant be inherited into sub class.
• Option - b is false because private member(variables) in super class can't be inherited to sub class as well.
• Object of a sublass(derived class) can be used to peroform same functionality as object of superclass(base class).

3. Choice(D) is correct, ie., All of the above

• Pair programming benefits include collective ownership of codes, multiplied learning among peers, code critics in a constructive way, refinement , building trust among employees etc.