多重繼承和繼承的數據成員在派生類構造函數初始化列表中

Question

我寫了一個簡單的程序來處理重複繼承。 我用一個基類，兩個子類和孫子類

class Parent{ 
public: 
Parent(string Word = "", double A = 1.00, double B = 1.00): sWord(Word), dA(A), dB(B){ 
} 


//Member function 
void Operation(){ 
cout << dA << " + " << dB << " = " << (dA + dB) << endl; 
} 

protected: 
string sWord; 
double dA; 
double dB; 
}; 

現在，這裏是第一個子類

class Child1 : public Parent{ 
public: 
//Constructor with initialisation list and inherited data values from Parent class 
Child1(string Word, double A, double B , string Text = "" , double C = 0.00, double D = 0.00): Parent(Word, A, B), sText(Text), dC(C), dD(D){}; 


//member function 
void Operation(){ 
cout << dA << " x " << dB << " x " << dC << " x " << dD << " = " << (dA*dB*dC*dD) << endl;} 

void Average(){ 
cout << "Average: " << ((dA+dB+dC+dD)/4) << endl;} 


protected: 
string sText; 
double dC; 
double dD; 
}; 

這裏是老二類

class Child2 : public Parent { 
public: 
//Constructor with explicit inherited initialisation list and inherited data values from Base Class 
Child2(string Word, double A, double B, string Name = "", double E = 0.00, double F = 0.00): Parent(Word, A, B), sName(Name), dE(E), dF(F){} 


//member functions 
void Operation(){ 
cout << "(" << dA << " x " << dB << ") - (" << dE << "/" << dF << ")" << " = " 
    << (dA*dB)-(dE/dF) << endl;} 

void Average(){ 
cout << "Average: " << ((dA+dB+dE+dF)/4) << endl;} 

protected: 
string sName; 
double dE; 
double dF; 
}; 

這裏處理多重繼承的孫子類

class GrandChild : public Child1, public Child2{ 
public: 
//Constructor with explicitly inherited data members 
GrandChild(string Text, double C, double D, 
       string Name, double E, double F): Child1(Text, C, D), Child2(Name, E, F){} 


//member function 
void Operation(){ 
cout << "Sum: " << (dC + dD + dE + dF) << endl; 
} 

}; 

在主函數中我然後創建一個孫子對象並初始化它像這樣：

GrandChild gObj("N\A", 24, 7, "N\A", 19, 6); 

//calling the void data member function in the GrandChild class 
gObj.Operation(); 

的答案，我去，這是

SUM: 0 

但是答案應該是56！顯然，正在使用GrandChild類的構造函數中使用的默認繼承值，而不是包含在構建GrandChild對象中的數據值。我怎麼解決這個問題？

Answer 1

爲了讓代碼工作，我想我做了這些改變

//Constructor with explicitly inherited data members 
GrandChild(string Word, double A, double B, string Text, double C, double D, 
     string Name, double E, double F): 
      Child1(Word, A, B, Text, C, D), 
       Child2(Word, A, B, Name, E, F){ } 

基本上每個子類繼承了自己獨立的父類。此父類的數據成員出現在兩個子類構造函數列表中。在構造GrandChild類時，我將這些值聲明爲其構造函數中的參數（僅用於避免重複）！我還包括繼承的子類。

在主然後我可以像這樣創建一個孫子對象：

GrandChild gObj("n\a", 0.00, 0.00, "text", 3, 3, "text", 3, 3, 7); 

並使用點運算符和無效的成員函數我得到正確的答案：

gObj.Operation() 

是：

sum: 12