使用虚函数的C ++

我的程序为每个客户输出一组奇怪的数字，但没有得到每个客户的名字。我不确定我是否正确使用了虚函数，因为从概念上讲，这对我来说是相对较新的东西。

每个类别都使用Compute_Bill（）函数，因为Premium_Customer对帐单的计算方式与正常客户不同。我已注释掉每个账单的计算成本。

main（）函数只是用于为每个人建立一个具有不同名称和呼叫次数的列表，因此该程序应该显示两种不同定价计划的示例。

这是输出：

客户欠10美元。

客户欠20.4美元。

客户欠-7.02934e + 114美元。

客户欠20.4美元。

客户欠10美元。

客户欠20.4美元。

客户欠10美元。

客户欠20.4美元。

客户欠10美元。

客户欠20.4美元。

客户欠10美元。

客户欠20.4美元。

客户欠10美元。

客户欠20.4美元。

客户欠10美元。

客户欠20.4美元。

客户欠10美元。

客户欠款1.24244e + 150美元。

这是我的程序，从上到下从客户类开始，然后是高级类，然后是主类：

#include <iostream>

using namespace std;

// CUSTOMER CLASS
class Customer
{
private:
    double numCalls;
    string name;
    const double MONTH_FEE = 10;
    const double PER_CALL = .5;

protected:
    double bill;

public:
    Customer();
    Customer(string aName, double aCalls);
    virtual double Compute_Bill();
    string getName();
    void setName(string aName);
    double getCalls();
    void setCalls(double aCalls);
};

Customer::Customer()
{
}

Customer::Customer(string aName, double aCalls)
{
    aName = "";
    aCalls = 0;
}

string Customer::getName()
{
    return name;
}

void Customer::setName(string aName)
{
    aName = name;
}

double Customer::getCalls()
{
    return numCalls;
}

void Customer::setCalls(double aCalls)
{
    aCalls = numCalls;
} 

// Computing the bill for the Customer, uses
// bill = monthlyfee + (percallrate * numcalls)
// monthly fee = $10
// per call charge = .50
double Customer::Compute_Bill()
{
    bill = MONTH_FEE + (PER_CALL * numCalls);
    return bill;
}


// PREMIUM_CUSTOMER CLASS
class Premium_Customer : public Customer
{
private:
    double numCalls;
    string name;
    const double MONTH_FEE = 20;
    const double PER_CALL = .05;
    const double PER_MINUTE = .1;
    const double NUM_MINS = 4;

protected:
    double bill;

public:
    Premium_Customer();
    Premium_Customer(string aName, double aCalls);
    virtual double Compute_Bill();
    string getName();
    void setName(string aName);
    double getCalls();
    void setCalls(double aCalls);
};

Premium_Customer::Premium_Customer()
{
}

Premium_Customer::Premium_Customer(string aName, double aCalls)
{
    aName = "";
    aCalls = 0;
}

string Premium_Customer::getName()
{
    return name;
}

void Premium_Customer::setName(string aName)
{
    aName = name;
}

double Premium_Customer::getCalls()
{
    return numCalls;
}

void Premium_Customer::setCalls(double aCalls)
{
    aCalls = numCalls;
}

// Computing the bill for the Premium_Customer, uses
// bill = monthlyfee + (percallrate * numcalls) + (permin_callrate *   nummins)
// monthly fee = $20
// per call charge = .05
// per minute call rate = .10
// nummins = 4
double Premium_Customer::Compute_Bill()
{
    bill = MONTH_FEE + (PER_CALL * numCalls) + (PER_MINUTE * NUM_MINS);
    return bill;
}

// MAIN CLASS
int main () {
    Customer* list[18] ;
    list[0] = new Customer("John Dough", 20);
    list[1] = new Premium_Customer("Bob Dough", 20);
    list[2] = new Customer("Tim Dough", 30);
    list[3] = new Premium_Customer("Jane Dough", 30);
    list[4] = new Customer("Bill Dough", 40);
    list[5] = new Premium_Customer("Tom Dough", 40);
    list[6] = new Customer("Jim Dough", 50);
    list[7] = new Premium_Customer("Kane Dough", 50);
    list[8] = new Customer("Hon Dough", 60);
    list[9] = new Premium_Customer("Jill Dough", 60);
    list[10] = new Customer("Mary Dough", 70);
    list[11] = new Premium_Customer("Un Dough", 70);
    list[12] = new Customer("Sarah Dough", 80);
    list[13] = new Premium_Customer("Liz Dough", 80);
    list[14] = new Customer("Will Dough", 90);
    list[15] = new Premium_Customer("Mike Dough", 90);
    list[16] = new Customer("Brian Dough", 100);
    list[17] = new Premium_Customer("Kurt Dough", 100);
    for(int i=0; i<18; i++) {
        cout << "Customer " << list[i]->getName() << " owes "
        << list[i]->Compute_Bill() << " dollars." << endl;
    }
    // delete all the customers
    return 1;
}