MidtermA

Question 1

1. Which of the following commands would you use to create an object file Student.o
   for a Student class (assuming there is a Student.h and a Student.cc file)?

(a) g++ -c Student.cc
(b) g++ -o Student.o Student.cc
(c) g++ -c Student.h
(d) g++ Student.cc Student.h

Answer 1

(a) g++ -c Student.cc

Question 2

2. What would be the output of the following code assuming the user entered a 5?
   ~~~
   # include < iostream >
   # include < string >
   using namespace std ;
   void doubleNum ( int num ){
   num *= 2;
   }
   int main (){
   int num ;
   cout «” Enter an integer : “ ;
   cin&raquo_space; num ;
   doubleNum ( num );
   cout &laquo_space;” Your number doubled is : “ &laquo_space;num &laquo_space;endl ;
   }
   ~~~
   (a) 2
   (b) 5
   (c) 10
   (d) Error

Answer 2

(b) 5

Question 3

3. Which of these functions could return an int as an output parameter?

(a) int& getValue();
(b) void getValue(int*);
(c) void getValue(int);
(d) int* getValue();

Answer 3

(b) void getValue(int*)

Question 4

5. Assuming there is a Date class, which of these functions would result in the copy
   constructor of the Date class being called?

(a) bool beforeDate(Date&);
(b) bool beforeDate(Date*);
(c) bool beforeDate(Date);
(d) None of these.

Answer 4

(c) bool beforeDate(Date);

Question 5

6. What is the output of the following code?
   ~~~
   # include < iostream >
   using namespace std ;
   class Egg {
   public :
   Egg ( string size = “ mini “ ){ cout &laquo_space;” Egg ctor “ ; }
   private :
   string size ;
   };
   class Chicken {
   public :
   Chicken (){ cout &laquo_space;” Chicken ctor “ ; }
   private :
   Egg egg ;
   };
   int main (){
   Chicken chicky ;
   }
   ~~~

(a) Egg ctor Chicken ctor
(b) Chicken ctor Egg ctor
(c) Chicken ctor
(d) None of these.

Answer 5

(a) Egg ctor Chicken ctor

Question 6

7. If Student* stu is a pointer to a Student object, which of these is the proper way to
   assign this pointer to a double pointer output parameter?

(a) void getStudent(Student** student){
*student = stu;
}
(b) void getStudent(Student** student){
student = &stu;
}
(c) void getStudent(Student** student){
&student = *stu;
}
(d) void getStudent(Student** student){
**student = *stu;
}

Answer 6

(a) void getStudent(Student** student){
*student = stu;
}

Question 7

8. Which of these variables could be used to refer to a statically allocated array of Student
   pointers?

(a) Student** studentArray;
(b) Student* studentArray;
(c) Student& studentArray;
(d) Student studentArray;
(e) None of these.

Answer 7

(a) Student** studentArray;

Question 8

9. Which of these variables could be used to refer to a dynamically allocated array of
   Student objects?

(a) Student** studentArray;
(b) Student* studentArray;
(c) Student& studentArray;
(d) Student studentArray;
(e) None of these.

Answer 8

(b) Student* studentArray;

Question 9

include < iostream >

10. How many int variables are allocated on the function call stack in this program?
    ~~~
    using namespace std ;
    int main (){
    int x = 0;
    int y = x ;
    int & z = x ;
    z = 10;
    int * w = & y ;
    cout &laquo_space;w «” , “ &laquo_space;x «” , “ &laquo_space;y «” , “ &laquo_space;z ;
    }
    ~~~

(a) 2
(b) 1
(c) 3
(d) 4
(e) 10
(f) None of these.

Answer 9

(a) 2

Question 10

11. Which of the following is NOT an example of an object category?

(a) Entity objects
(b) Control objects
(c) Boundary objects
(d) Dynamically allocated objects

Answer 10

(d) Dynamically allocated objects

Question 11

12. Which of these is NOT shown in a UML diagram? (select all that apply)

(a) Constructors
(b) Collection classes
(c) Member variables
(d) Private functions

Answer 11

(a) Constructors
(b) Collection classes

Question 12

13. Assuming these are functions in an Employee class with a pay member variable, which
    of these functions should be made const? Select all that apply.

(a) float getPay(){
return pay;
}
(b) void setPay(float pay){
this->pay = pay;
}
(c) bool lessThan(float pay) {
return this->pay < pay;
}
(d) Employee (Employee& e){
pay = e.pay;
}

Answer 12

(a) float getPay(){
return pay;
}
(c) bool lessThan(float pay) {
return this->pay < pay;
}

Question 13

14. Which of these are valid ways to initialize the nextId variable in the Employee class
    above (select all that apply)?
    ~~~
    class Employee {
    private :
    static int nextId ;
    }
    ~~~

(a) static int nextId = 100;
(b) static int Employee::nextId = 100;
(c) Employee::Employee(int nextId): nextId(nextId)
(d) int Employee::nextId = 100;

Answer 13

(d) int Employee::nextId = 100;

Question 14

15. When running the following piece of code, what part of memory would the Weapon
    object be stored?
    ~~~
    # include < iostream >
    # include < string >
    using namespace std ;
    class Weapon {
    public :
    Weapon ( int damage ){ this - > damage = damage ;}
    private :
    int damage ;
    };
    class Character {
    public :
    Character ( const string & n , int h , int damage ){
    name = n ;
    health = h ;
    weapon = new Weapon ( damage );
    }
    private :
    string name ;
    int health ;
    Weapon * weapon ;
    };
    int main (){
    Character joe ( “ Joe “ , 20 , 20);
    }
    ~~~

(a) No Weapon object was created.
(b) The heap.
(c) The function call stack.
(d) Both the heap and the function call stack.

Answer 14

(b) The heap.