问题是通过添加两个类的友元函数来访问两个不同类输出的私有(private)变量。
class Salesperson;
class Sale {
private:
string date;
double total;
int SalespersonIdNum;
public:
Sale(string, double, int);
friend void display(Sale &, Salesperson &);
};
Sale::Sale(string d, double t, int S) {
>>d = date;
>>t = total;
>>S = SalespersonIdNum;
}
//Salesperson class
class Salesperson {
private:
int idNum;
string lastName;
public:
Salesperson(int, string);
friend void display(Sale &, Salesperson &);
};
Salesperson::Salesperson(int i, string l) {
>>i = idNum;
>>l = lastName;
}
void display(Sale &s, Salesperson &sp) {
//Output Sale info
cout << " ID of person who completed sale: " << s.SalespersonIdNum << endl;
cout << " Sale Total: " << s.total << endl;
cout << " Sale Date: " << s.date << endl;
//Output Saleperson info
cout << " Sales Person ID: " << sp.idNum << endl;
cout << " Sales Person Last Name: " << sp.lastName << endl << endl;
}
int main() {
Sale s1("10/06/2008", 78.45, 123);
Salesperson emp1(123, "Pelletier");
display(s1, emp1);
Sale s2("05/21/2010", 162.59, 321);
Salesperson emp2(321, "Howel");
display(s2, emp2);
return 0;
}
理想情况下，显示函数应该能够访问由我的对象定义定义的变量，但是当我去运行并显示它们时，函数会显示这个。
ID of person who completed sale: 124
Sale Total: 2.07482e-317
Sale Date:
Sales Person ID: 6299816
Sales Person Last Name:
ID of person who completed sale: 1677231376
Sale Total: 2.07417e-317
Sale Date:
Sales Person ID: 1
Sales Person Last Name:
...Program finished with exit code 0
Press ENTER to exit console.
根据我的理解，友元函数应该像那样工作，但问题可能出在构造函数中，但我认为它们也正确完成了。至于输出可能我输出内存地址什么的，但我对此一无所知
最佳答案
您的分配在构造函数中的方向错误。
Sale::Sale(string d, double t, int S) {
d = date;
t = total;
S = SalespersonIdNum;
}
他们需要:
Sale::Sale(string d, double t, int S) {
date = d;
total = t;
SalespersonIdNum = S;
}
最好使用列表初始化语法。
Sale::Sale(string d, double t, int S) :
date(d),
total(t),
SalespersonIdNum(S) { }
关于c++ - 创建友元函数以访问两个类的私有(private)变量，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50517343/