Question

#include<iostream>
#include<string>
using namespace std;
//class definition
class BankCustomer
{
public:
    BankCustomer();     //constructor for BankCust class
    void fullname(string, string);
    string firstname();
    string lastname();
    bool setsocial(int s); //accept a arg. of int type
    int getsocial();
private:
    string fname, lname; 
    int SSNlength;  //can't be changed by client; sensitive info should be made private
};

//class implementation
BankCustomer::BankCustomer(){}

void BankCustomer::fullname(string f, string l)
{
    fname=f;
    lname=l;
}

string BankCustomer::firstname()
{
    return fname;
}

string BankCustomer::lastname()
{
    return lname;
}

bool BankCustomer::setsocial(int s)
{
    int count, SSNlength;
    while(s != 0)
    {
        s /=10;             //counts number of integers; count goes to max of ten
        ++count;
        if(count == 9)
        {
            cout <<"\nValid SSN Entered!" << endl;
            SSNlength=s;
            return true;
        }
    }
}

int BankCustomer::getsocial()
{
    return SSNlength;
}

//client program
int main()
{
    BankCustomer customer;          //customer declared as object of BankCust class
    string firstname, lastname;
    int ssn, s;

    //data assignment
    cout <<"\n Enter First Name\n" << endl;
    cin >> firstname;

    cout<<"\n Enter Last Name\n"<< endl;
    cin >> lastname;

    customer.fullname(firstname,lastname);

    do
    {
        cout<<"\nEnter 9-Digit SSN"<< endl;
        cin >> ssn;
    }
    while(!customer.setsocial(ssn)); //function will repeat as long as entered user ssn forces social() to evaluate it as false

    //data ouput
    cout <<"\nFirst Name:  "<<customer.firstname()<<"\n"<< endl;
    cout <<"\nLast Name:  "<<customer.lastname()<<"\n"<< endl;
    cout <<"\n SSN is:  "<<customer.getsocial()<<"\n" << endl;      //not printing correct value
}

当我运行程序时，输入的姓名的用户输入正确打印到屏幕上。但是，当我尝试打印输入的SSN值时，程序会返回一个与输入的用户不匹配的垃圾值。在customer.getsocial()行打印cout<<"\n SSN is:的返回值时会出现问题。

Answer 1

您的成员变量SSNlength是未初始化的，而您在

中的setsocial（int s）中定义了具有相同名称的局部变量

int count, SSNlength;

因此，您的成员变量将不会被初始化，因为您的局部变量隐藏它，这意味着getsocial（）将始终返回垃圾...

此外，如果您的输入 s 无效以避免未定义的行为，则应该从setsocial（int s）返回false。可能像

bool BankCustomer::setsocial(int s)
{
  SSNlength = s;
  int count;
  while(s != 0)
  {
    s /=10;
    ++count;
    if(count == 9)
    {
       cout <<"\nValid SSN Entered!" << endl;
       return true;
    }
  }
  return false;
}

用户输入值，但任意值打印到屏幕。印刷值不匹配输入值

1 个答案: