Checkpoint 15.14 (page 951)

#include using namespace std;

class First

{

protected: int a;

public:

First(int x = 1) { a = x; } virtual void twist() { a *= 2; } int getVal() { twist(); return a; }

}; class Second : public First

{

private: int b;

public: Second(int y = 5) { b = y; } virtual void twist() { b *= 10; }

};

1. int main()

2. {

3. First object1;

4. Second object2;

5.

6. cout << object1.getVal() << endl;

7. cout << object2.getVal() << endl;

8. return 0;

9. }

a) What is the output of this program?

b) At line 5, what are the member variable(s) of object1? What are their value(s)?

c) At line 5, what are the member variable(s) of object2? What are their value(s)?

d) At line6, which twist() function is called, First::twist() or Second::twist()?

e) At line6, which twist() function is called, First::twist() or Second::twist()?

Checkpoint 15.15 (page 952)

#include using namespace std; class Base

{

protected: int baseVar;

public: Base(int val = 2) { baseVar = val; } int getVar() { return baseVar; }

};

class Derived : public Base

{

private: int derivedVar; public: Derived(int val = 100) { derivedVar = val; } int getVar() { return derivedVar; }

};

int main()

{ Base *optr = nullptr; Derived object; optr = &object; cout << optr->getVar() << endl; return 0;

}

a) What is the output of this program?

b) What does this program demonstrate?