Error: pure virtual method called - terminate called without an active exception - Aborted

Question

In my A.h file:

class A{
  private:
    unsigned short PC;
  public:
    A():PC(0){}
    virtual ~A(){}
    virtual void execute(unsigned short PC)=0;
};


        

Answer 1

int main(int args, char**argv){
    A *a;
    B b; // wrong
    a = &b; // wrong
    Functions f;
    f.run(a);
    return 1;
}

you can do this :

int main(int args, char**argv){
    A *a = new B;
    //B b;
    //a = &b;
    Functions f;
    f.run(a);
    return 1;
}

Answer 2

Usually you get this error when call your virtual function from constructor or destructor. Check that that is not the case.

(I assume that your demo code is not complete).

Answer 3

Don't know what you're doing but this, which is basically what you're showing us, except that is simplified and actually compiling, runs without any problems:

#include <iostream>

class A
{
public:
   virtual ~A() {}
   virtual void execute() = 0;
};

class B: public A
{
public:
   virtual void execute() {std::cout << "B::execute" << std::endl;}
};

void execute(A* a)
{
   a->execute();
}

int main()
{
   A* a;
   B b;
   a = &b;

   execute(a);

   return 0;
}

Answer 4

You wrote B() constructor without paranthesis , plus you have 2 B() default constructors, plus one of them is virtual(not good), plus when you execute a->execute, again you need paranthesis with an argument, because it is a function:

Try this:

#include <iostream>
using namespace std;

class A{
private:
unsigned short PC;
public:
A():PC(0){}
virtual ~A(){}
virtual void execute(unsigned short PC)=0;
};


class B:public A{
private:
    int status;
    bool exe;
public:
B():status(0),exe(false){}
//virtual B(){}
void execute (unsigned short PC);
};



void B::execute (unsigned short PC){
cout << "Run";
}



class Functions{
public: int status;
Functions():status(1){} // this is a constructer
void run(A *a);
};


void Functions::run (A *a){
a->execute(1);
}


int main(int args, char**argv){
A *a;
B b;
a = &b;
Functions f;
f.run(a);
return 1;
}