c++ - 在 C++ 类继承中使用函数

Question

我正在尝试调用此类中的函数 calculateInterest()

// account.h -- handles banking accounts
#ifndef ACCOUNT_H_
#define ACCOUNT_H_
#include <string>
using std::string;

class Account
{
private:
    double balance;
public:
    Account(double b = 0.0);
    double getBalance() {return balance;}
    void credit(double c);
    void debit(double d); 
};

class SavingsAccount : public Account
{
private:
    double rate;
public:
    SavingsAccount(double r = 0.0);
    double calculateInterest();
};



class CheckingAccount : public Account
{
private:
    double fee;
public:
    CheckingAccount(double f = 0.0);
    void credit(double m);
    void debit(double m);
};


#endif

到目前为止，我可以执行 Account joe(100); 然后使用 Account 类中的函数，所以我显然没有正确继承它。

Answer 1

class Account
{
private:
    double balance;
public:
    Account(double b = 0.0);
    double getBalance() {return balance;}
    void credit(double c);
    void debit(double d);

    // add this!
    virtual double calculateInterest() = 0;
};

您需要在所有派生类中实现 calculateInterest