Programming & Computer Science Answers

Write output of given code segments and explain it logically, answer without explanation will be awarded zero marks. 

a)  

#include<iostream>

using namespace std;

class Base

{

public:

    virtual void show() { cout<<" In Base \n"; }

};

class Derived: public Base

{

public:

    void show() { cout<<"In Derived \n"; }

};

int main(void)

{

    Base *bp = new Derived;

    bp->show();

    Base &br = *bp;

    br.show();

    return 0;

}

Answer the following short questions. Your answer should be precise.

a)     Can we declare base class constructor or destructor as virtual if yes then why we want to do?

b)    How we can declare a class as abstract and why we need abstract classes? 

c)     Why we cannot able to create objects of abstract classes give reasonable justification of that.           

Create a class template for a class named GeneralStackthat holds

• A single data member as an array named stack of size 50 to store certain elements.
• Three member functions i.e. push(type) to add elements in the Stack, pop() to remove elements from the stack, and currentStatus() to check whether the array is filled or not. (A filled array is an array that has non-zero value at all of its indexes).

In the main() function, create three objects with different data types of class General Stack and test the functionality of member functions for various values of data members for these objects.

Create a class called Transmitter. It has three unsigned int private data members: pay_load,

parity and data_packet; It has one function called parity_bit(). It calculates parity bit by XORing

all pay_load bits and assign the value to parity. By using function get pay_load(), pay_load is got.

data_packet is calculated by multiplying parity_bit with 32768 and add the product with (pay_load

– 32768). Create another class called Receiver. It has unsigned int private data members Rx_Pkt

, Rx_Data and E_Flag. Rx_Data is got from Rx_Data as given below. First E_Flag is calculated

from Rx_Pkt by XORing all bits. If E_Flag is zero, then Rx_Data = Rx_Pkt – 32768, Else a

message should warn about corrupted packet. Derive a class called Tranceiver from the above two

classes and check the functionalities. Use any other functions if needed.

Write a program that has a class Train with data members seats_first_class, seats_second_class

and seats_ac_2tier and member functions to set and display data. Derive a class Reservation that has

data members booked_first_class, booked_second_class and booked_ac_2tier and functions to book

and cancel tickets and display status.

Write a program for a publishing company that markets both printed books and audio visual

lectures stored on CDs. Write a class Publication thatstores title and price. Derive a class book which

has an additional member as no_pages and a class Lecture with member play_time.

Write a program of c++ with a following statement: A person can be an employee or a student. An employee may have rights of admin officer or of

academic officer. These class hierarchies represent multi-level inheritance. However, a Dean or

Head of Department(HOD) may have rights to modify the status already defined by an administrator

academic officer. Implement all these classes with appropriate data members and proper suitable

functions and within the main function, create instances of all classes and test the described working

of all these classes.

Design a class that has an array of floating-point numbers. The constructor should accept an 

integer argument and dynamically allocate the array to hold that many numbers. The 

destructor should free the memory held by the array. In addition, there should be member 

functions to perform the following operations:

• Store a number at any index of the array

• Retrieve a number from any index of the array.

Return the highest value stored in the array

• Return the lowest value stored in the array

• Return the average of all the numbers stored in the array.

Answer the following short questions. Your answer should be precise.

a)     Can we declare base class constructor or destructor as virtual if yes then why we want to do?

b)    How we can declare a class as abstract and why we need abstract classes? 

c)     Why we cannot able to create objects of abstract classes give reasonable justification of that.           

Write a program to print the following details

• Assign and print the ID of each employee,
• Phone number and Address of two staff members having names "ali" and "asif" respectively by creating two objects of the class 'Employee'.
• throw an exception in case the phone number of employee is inserted in float , double or char value.
• throw an exception in case the ID of an employee is inserted in float , double or char value.