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Question

我必须创建一个简单的类，它有几个子类，其中一个子类有它自己的子类。

AccountClass.h

#ifndef Account_h
#define Account_h

class Account{

public:
    //Account(){balance = 0.0;}; Here's where the problem was
    Account(double bal=0.0){ balance = bal;};
    double getBal(){return balance;};

protected:
    double balance;
};
#endif

SavingsAccount.h

#ifndef SavingsAccount_h
#define SavingsAccount_h
#include "AccountClass.h"
class SavingsAccount : public Account{

public:
    //SavingsAccount(); And here
    SavingsAccount(double bal = 0.0, int pct = 0.0){ balance = bal; rate = pct; } : Account(bal);
    void compound(){ balance *= rate; };
    void withdraw(double amt){balance -= amt;};

protected:
    double rate;
};

#endif

CheckingAccount.h

#ifndef CheckingAccount_h
#define CheckingAccount_h
#include "AccountClass.h"
class CheckingAccount : public Account{

public:
    //CheckingAccount(); Here also
    CheckingAccount(double bal = 0.0, double lim = 500.0, double chg = 0.5){ balance = bal; limit = lim; charge = chg;} : Account(bal);
    void cash_check(double amt){ balance -= amt;};

protected:
    double limit;
    double charge;
};

#endif

TimeAccount.h

#ifndef TimeAccount_h
#define TimeAccount_h
#include "SavingsAccount.h"
class TimeAccount : public SavingsAccount{

public:
    //TimeAccount(); ;)
    TimeAccount(double bal = 0.0, int pct = 5.0){ balance = bal; rate = pct;} : SavingsAccount(bal,pct);
    void compound(){ funds_avail += (balance * rate); };
    void withdraw(double amt){funds_avail -= amt;};

protected:
    double funds_avail;
};

#endif

我不断收到错误消息，指出已定义默认构造函数以及所有不存在的变量...

帮助!

编辑:

修复了预处理器 ifndef 的

另外，这个问题已经解决了。谢谢@Coincoin!

Answer 1

您没有定义默认构造函数，但是当您派生新类时默认会调用它们。看起来 TimeAccount 将是该问题的罪魁祸首，因为它使用 SavingsAccount 的默认构造函数。然而，它们都应该被定义，而不仅仅是声明。