When the fictitious functions of the derived class and the base class are passed with different real parameters by default

When the fictitious functions of the derived class and the base class have different real parameters by default;

The arguments of a derived class receive the default parameters passed by the base class.

The columns are as follows:

 

 

[Cpp]
# Include <iostream>
# Include <ostream>
# Include <string>
Using namespace std;
Class B {
Public:
Virtual void fun (int num = 0)
{
Cout <"B =" <num <endl;
}
};
Class D: public B {
Public:
Virtual void fun (int num = 1)
{
Cout <"D =" <num <endl;
}
};
Int main ()
{
D;
B * p = & d;
P-> fun ();
B & B = d;
B. fun ();
Return 0;
}

# Include <iostream>
# Include <ostream>
# Include <string>
Using namespace std;
Class B {
Public:
Virtual void fun (int num = 0)
{
Cout <"B =" <num <endl;
}
};
Class D: public B {
Public:
Virtual void fun (int num = 1)
{
Cout <"D =" <num <endl;
}
};
Int main ()
{
D;
B * p = & d;
P-> fun ();
B & B = d;
B. fun ();
Return 0;
}

The running result is as follows:

D = 0
D = 0