Question

please help code in c++, assignment stats below dashed line

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In this lab we will practice polymorphism using several different classes. Implement your classes in B.h and test them in main.cpp:

B.h

• Define a class B1 with:
  • virtual function vf()
  • non-virtual function f()
  • pure virtual function pvf()
  • Define these functions within class B1
  • Implement each function to output its name (e.g., B1::vf()).
  • Make the functions public.
• Derive a class D1 from B1
  • Define f()
  • override vf()
  • override pvf()
• Derive a class D2 from D1
  • override pvf()
• Define a class B2 with a pure virtual function pvf()
• Derive a class D21 from B2 with a string data member and a member function that overrides pvf()
  • Initialize the string to "D21::pvf()"
  • D21::pvf() should output the value of the string and a newline
• Define a class D22 that is just like D21 except that its data member is an int
  • Initialize the int to 22
  • Your output only needs to output the integer value and a newline
• Define a global function f() that takes a B2& argument and calls pvf() for its argument.

main.cpp

• Try to create a B1 object. What does the compiler tell you? Why?
• Make a D1 object and call f(), vf(), and pvf() for it
• Define a reference to B1 (a B1&) and initialize that to the D1 object you just defined.
• Call f(), vf(), and pvf() for that reference.
• Make an object of class D2 and call f(), vf(), and pvf() for it.
• Make a D21 and a D22 object
• Call f() with a D21 and a D22

Answer 1

ANSWER:

#include<iostream>
using namespace std;
//Define a class B1 with:
//virtual function vf()
//non-virtual function f()
//pure virtual function pvf()
class B1{
public:
virtual void vf();
void f();
virtual void pvf()=0;
};
void B1::vf()
{
cout<<"This is B1's virtual function "<<endl;
}
void B1::f()
{
cout<<"This is B1's non-virtual function"<<endl;
}
//Derive a class D1 from B1
//Define f()
//override vf()
//override pvf()
class D1 : public B1
{
public :
void f()
{
cout<<"This is D1's non-virtual function"<<endl;
}
void vf()
{
cout<<"This is D1's Overridden virtual function"<<endl;
}
void pvf()
{
cout<<"This is D1's Overridden pure-virtual function"<<endl;
}

};
//Derive a class D2 from D1
//override pvf()
class D2 : public D1
{
public:
void pvf()
{
cout<<"This is D2's Overridden pure virtual function"<<endl;
}
};
//Define a class B2 with a pure virtual function pvf()
class B2
{
public :
virtual void pvf()=0;
};

//Derive a class D21 from B2 with a string data member and a member function that overrides pvf()
//Initialize the string to "D21::pvf()"
class D21 :public B2
{
private:
string name="D21::pvf()";
public:
void pvf();
};
void D21::pvf()
{
cout<<name<<endl;
}
//Define a class D22 that is just like D21 except that its data member is an int
//Initialize the int to 22
class D22:public B2
{
private :
int data=22;
public:
void pvf();

};
void D22::pvf()
{
cout<<data<<endl;
}
//Define a global function f() that takes a B2& argument and calls pvf() for its argument.
void f(B2& b2)
{
b2.pvf();
}
//*****************************************main.cpp *******************************************

#include <iostream>
#include "B.h"
using namespace std;
int main()
{
//Make a D1 object and call f(), vf(), and pvf() for it
D1 d1;
d1.f();
d1.vf();
d1.pvf();
//Define a reference to B1 (a B1&) and initialize that to the D1 object you just defined.
B1* b1;
b1=&d1;
//Call f(), vf(), and pvf() for that reference.
b1->f();
b1->vf();
b1->pvf();
//Make an object of class D2 and call f(), vf(), and pvf() for it.
D2 d2;
d2.f();
d2.vf();
d2.pvf();
//Make a D21 object
D21 d21;
//Call pvf() with a D21
d21.pvf();
//Make a D21 object
D22 d22;
//Call pvf() with a D21
d22.pvf();
return 0;
}
//Ouput

Q.Try to create a B1 object. What does the compiler tell you? Why?

Answer: We can not create B1 object ,Compiler will give your error because this is a abstract class due to pure virtual function .We can't create object of abstract class.

CAUsershpDocumentscodeBlockogramabc.exe This is D1's non-virtual function This is D1's Overridden virtual function This is D1's Overridden pure-virtual function This is B1's non-virtual function This is D1's Overridden virtual function This is D1's Overridden pure-virtual function This is D1's non-virtual function This is D1's Overridden virtual function This is D2's Overridden pure virtual function D21: :pvfO Process returned e (ex execution time e.362 s Press any key to continue