重载<< operator c ++的输出不正确

Question

我有Class NumDays如下所示:

Class NumDays
{
   private:
      double hours;

   public:
      NumDays() { hours = 0.0; }            //default constructor
      NumDays(double hr) { hr = hours; }    //initializing constructor  

   //Large class, nothing of importance, rest of class omitted

   //overloading << operator
    friend ostream &operator<<(ostream &out, NumDays a);
}

我有NumDay.cpp 这包括:

ostream &operator<<(ostream& out, NumDays a)
{
   // takes amount of hours, computes to work days

   int temp = a.hours / 8;

   //gives remainder of hours after full 8 hr workday.

   double hrs = a.hours - (temp * 8);

   //outputs 
   cout << fixed << setprecision(0);
   out << (a.hours / 8) << " Days, " << hrs << "hours";
    return out;
}

我必须main.cpp包括:

int main()
{
   // Initialized UDT object Declarations
   NumDays hoursWorked_John;       // Instantiate with Default Constructor
   NumDays hoursWorked_Sue(36.9);  // Instantiate with Initializing Cons      
   NumDays hoursUsed_Sue(4.5);     // Instantiate with Initializing Cons

   cout << "John's initial hours worked: " << hoursWorked_John << endl;
   hoursWorked_John.addHours(56.78);
   cout << "  John's final hours worked: " << hoursWorked_John << endl;

   cout << "Sue's initial hours worked: " << hoursWorked_Sue << endl;

   //rest of main omitted for sake of size

当我去运行程序的这一小部分时,这是我的控制台:

任何关于为什么苏的时间如此错误的想法,但约翰是正确的？

Answer 1

  NumDays(double hr) { hr = hours; }    //initializing constructor  

哎呦.在这里,您将成员保持hours未初始化状态并修改临时参数hr.你似乎是这个意思

  NumDays(double hr) { hours = hr; }

(或更好:)

  NumDays(double hr) : hours(hr) {}