Question

Need help with a multiple inheritance work

Question

Compile and run the file. If you find any compilation errors,explain their reason as comments in the code. Then fix the errors such that the program compiles and runs. Explain the motivation of your modifications in the code and their effects on the execution

inheritance.cpp file

#include<iostream>
using namespace std;

class A
{
int x;
public:
void setX(int i) {x = i;}
void print() { cout << x; }
};

class B: public A
{
public:
B() { setX(10); }
};

class C: public A
{
public:
C() { setX(20); }
};

class D: public B, public C {
};

int main()
{
D d;
d.print();
return 0;
}

Answer 1

Dear Student ,

As per requirement submitted above kindly find below solution.

Compile Error :

• The line in main() d.print(); causing compile time error as

  request for member ‘print’ is ambiguous

• Because class D is inheriting class B and class C
• hence need to change the line so that either print() from B or Print from C is called
• So for print() from B call as d.B::print();
• or for class c call as d.C::print();

Demonstration :

Here new c++ program with name "main.cpp" is created which contains below code.

main.cpp

#include<iostream>//header files
using namespace std;
class A //Class A
{
int x;
public:
void setX(int i) {x = i;}
void print() { cout << x; }
};
//Class B inheriting class A
class B: public A
{
public:
B() { setX(10); }
};
//Class C inheriting class A
class C: public A
{
public:
C() { setX(20); }
};
//class D inheriting class C
class D: public B, public C {
};

int main()
{
D d;
d.B::print();//change this line
return 0;
}

==================================

Output :Compile and Run main.cpp to get the screen as shown below

Screen 1:For  d.B::print(); output is

Screen 2:For  d.C::print(); output is

NOTE :PLEASE FEEL FREE TO PROVIDE FEEDBACK ABOUT THE SOLUTION.