Exam 11: Inheritance and Composition

Consider the following class definitions: class bClass { public: $\quad$ void setX(int a); $\quad$$\quad$ //postcondition: x = a; $\quad$ void print() const; private: $\quad$ int x; }; class dClass: public bClass { public: $\quad$ void setXY(int a, int b); $\quad$$\quad$ //postcondition: x = a; y = b; $\quad$ void print() const; private: $\quad$ int y; }; Which of the following correctly sets the values of x and y?

Existing classes, from which you create new classes, are called ____ classes.

If the corresponding functions in the base class and the derived class have the same name but different sets of parameters, then this function is ____ in the derived class.

Which of the following is true about a derived class?

What is the output of the following program? #include <iostream> Using namespace std; Class bClass { Public: $\quad$ void print() const; $\quad$ bClass(int a = 0, int b = 0); $\quad$$\quad$ //Postcondition: x = a; y = b; private: $\quad$ int x; $\quad$ int y; }; class dClass: public bClass { public: $\quad$ void print() const; $\quad$ dClass(int a = 0, int b = 0, int c = 0); $\quad$$\quad$ //postcondition: x = a; y = b; z = c; private: $\quad$ int z; }; int main() { $\quad$ bClass bObject(2, 3); $\quad$ dClass dObject(3, 5, 8); $\quad$ bObject.print(); $\quad$ cout << endl; $\quad$ dObject.print(); $\quad$ cout << endl; $\quad$ return 0 ; } void bClass::print() const { $\quad$ cout << x << " " << y << endl; } bClass::bClass(int a, int b) { $\quad$ x = a; $\quad$ y = b; } void dClass::print() const { $\quad$ bClass:print(); $\quad$ cout << " " << z << endl; } dClass::dClass(int a, int b, int c) : bClass(a, b) { $\quad$ z = c; }

In ____________________, the derived class is derived from a single base class.

Classes can create new classes from existing classes. This important feature ____.

C++ provides ____ functions as a means to implement polymorphism in an inheritance hierarchy, which allows the run-time selection of appropriate member functions.

A derived class cannot directly access public members of a base class.

The constructor of a derived class cannot directly access the ____________________ member variables of the base class.

Consider the following class definitions: class bClass { Public: $\quad$ void set(double a, double b); $\quad$$\quad$ //postcondition: x = a; y = b; $\quad$ void print() const; $\quad$ bClass(); $\quad$$\quad$ //postcondition: x = 0; y = 0; $\quad$ bClass(double a, double b); $\quad$$\quad$ //postcondition: x = a; y = b; private: $\quad$ double x; $\quad$ double y; }; class dClass: public bClass { public: $\quad$ void set(double a, double b, double c); $\quad$$\quad$ //postcondition: x = a; y = b; z = c; $\quad$ void print() const; $\quad$ dClass(); $\quad$$\quad$ //postcondition: x = 0; y = 0; z = 0 ; $\quad$ dClass(double a, double b, double c); $\quad$$\quad$ //Postcondition: x = a; y = b; z = c; private: $\quad$ double z; }; Which of the following dClass constructor definitions is valid in C++?

A derived class can directly access the protected members of the base class.

Which of the following statements about inheritance is true if memberAccessSpecifier is protected?

Consider the following class definition: class dClass: bClass { //class members list }; The class dClass is derived from the class bClass using the ____ type of inheritance.

The ____ members of an object form its internal state.

Which of the following is true about inheritance?

In multiple inheritance, the derived class has more than one base class.

____ is the ability to use the same expression to denote different operations.

Suppose that bClass is a class. Which of the following statements correctly derives the class dClass from bClass?

Consider the following class definitions: class bClass { public: $\quad$ void setX(int); $\quad$ void print() const; private: $\quad$ int x; }; class dClass: public bClass { public: $\quad$ void setXY(int, int); $\quad$ void print() const; private: $\quad$ int y; }; Which of the following statements correctly redefines the member function print of bClass?