Question

When a constructor in a superclass receives arguments, it is no longer a default constructor, right? For example

class a {
    public:
      int a;
      int b;
      a(int c, int d){
        cout<<"hello";
      };
} 

Now when I try to make a subclass, the program causes an error, it says “no default constructor is defined in the super class”. How can I solve this problem? I know that if I remove the arguments, everything is going to be fine but I’m told not to do so in my C++ test. Please help me figure it out.

Answer 1

You normally deal with this with an initializer list:

#include <iostream>

class a { 
public:
    a(int c, int d) { std::cout << c << " " << d << "\n"; }
};

class b : public a { 
public:
    b() : a(1, 2) {}
};

int main() { 
    b x;
    return 0;
}