从类成员函数打印结构输入

Question

I would like to know how to input/initialize a start_date and end_date (which comes from a structure Date that has integers of month day and year from the function `initializeDate. Once I am able to initialize I assume I will be able to use the same logic in the printout member function.

struct Date
{
    int month;
    int day;
    int year;
};


void initializeDate(Date &d)
{
    cout<<"Please enter the month"<<endl;
    cin>>start.month;
    cout<<"Please enter the day"<<endl;
    cin>>start.day;
    cout<<"Please enter the year"<<endl;
    cin>>start.year;
    string dummy;
    getline(cin, dummy);
}

edit: the error that I am getting is 'start' was not declared in this scope.

Answer 1

This is very basic, please read a good book on C++. Posting below because you have put in an effort :)

void Information::initializeDate(Date &d)    //comes from the Information class.
{
    // Commented as part of question change!  
    // Date d;     // Guessing that the structure is the private member of the class.
    cout<<"Please enter the month"<<endl;
    cin>>d.month;
    cout<<"Please enter the day"<<endl;
    cin>>d.day;
    cout<<"Please enter the year"<<endl;
    cin>>d.year;
    string dummy;
    getline(cin, dummy);
}

** Just Edited the code as per your change in question

Answer 2

It looks like you keep updating the example code. Based on the current revision, I think this is what you want:

#include <iostream>
using namespace std;

struct Date
{
    int month;
    int day;
    int year;
};


void initializeDate(Date &date)
{
    cout<<"Please enter the month"<<endl;
    cin>>date.month;
    cout<<"Please enter the day"<<endl;
    cin>>date.day;
    cout<<"Please enter the year"<<endl;
    cin>>date.year;
}

int main()
{
  Date start, end;
  initializeDate(start);
  initializeDate(end);
  cout << start.year << "/" << start.month << "/" << start.day << endl;
  cout << end.year << "/"   << end.month   << "/" << end.day << endl;
  return 0;
};

Answer 3

Ok, there are a couple of problems here, that you should target. First, to fix your code, the error is very simple: there isn't anywhere in your code in which a variable named start was declared/defined. So, the compiler is asking you what start is. You are trying, I assume, to initialize the values of the members of d, that you passed in the function initializeDate , and all you have to do is just replace every occurence of the word start with d , and you'll get:

void initializeDate(Date &d)
{
    cout<<"Please enter the month"<<endl;
    cin>> d.month;
    cout<<"Please enter the day"<<endl;
    cin>> d.day;
    cout<<"Please enter the year"<<endl;
    cin>> d.year;
    string dummy;
    getline(cin, dummy);
}

Now, although this works, it's not the best way to initialize the date. Since Date is a struct , you can initialize its members using a constructor method. This is achieved by writing it like this:

struct Date{
    int day, month, year;
    Date(int, int, int);
    };

Date:: Date(int day, int month, int year){
    this->day = day;
    this->month = month;
    this->year = year;
    }

int main(){
    Date today(11, 3, 2013);
    cout << "today, the date is " << today.day << "-" << today.month << "-" << today.year << endl; 
    return 0;
    }