How can you call a member function using a constructor?

The errors I am receiving before making the objects:

'getInFileS' was not declared in this scope| 'getInFileO' was not declared in this scope|

First line of each file has a number 100.

I thought I only needed to make objects to solve this issue such as:

Orders ord; Shipments ship;

ship.getInFileS(shipment, x, sFile); ord.getInFileO(order, x, oFile);

The errors I am receiving after making the objects:

undefined reference to Orders::Orders()'| undefined reference toShipments::Shipments()'| <-- line 172 undefined reference to `Shipments::Shipments()'| <-- line 192

I believe maybe I have made too many objects for Shipments and Orders. Am I using these default constructors right?

Thanks for everything!

Here is my code:

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <iomanip>

using namespace std;

struct Total{

    int dollars;
    int cents;
};

struct Date{

    int day;
    int month;
    int year;
};

struct SizeOfBox{

    int length;
    int width;
    int height;
};

struct Orders{

    string nameOrd;        /// Name of customer (small business)
    string nameItem;       /// Name of item needed
    int numBox;            /// Number of boxes
    Total total;           /// Total cost (dollar.cent)
    Date ordDate;          /// Date (month:day:year) order is placed

    /// Member functions orders
    bool compareDateHP();  /// Compare by date, if same, then by highest price
    void displayInFileO(Orders order[], int x);
    void getInFileO(Orders order[], int x, ifstream& inFile);

    /// Default constructor for orders
    Orders();
};
struct Shipments{

    string food;           /// Name of food item
    Date expDate;          /// Expiration date (month:day:year)
    SizeOfBox sizeBox;     /// Dimensions of the box (length:width:height) in inches
    int weight;            /// Weight of the box in pounds
    char bStorageM;        /// Best Storage Method (refrigerate “R”, freeze “F”, do not refrigerate “D”)
    Date recDate;          /// Date (month:day:year) received
    Total price;           /// Price (dollar.cent)

    /// Member functions for shipments
    bool compareEDate();  /// Compare by expiration date
    void displayInFileS(Shipments shipment[], int x);
    void getInFileS(Shipments shipment[], int x, ifstream& inFile);

    /// Default constructor for Shipments
    Shipments();
};

/// Using scope resolution operator, :: to access data types in the struct

void Orders::getInFileO(Orders order[], int x, ifstream& inFile){

    char decimal;

    for(int i = 0; i < x; i++){
        inFile >> order[i].nameOrd;
        inFile >> order[i].nameItem;
        inFile >> order[i].numBox;
        inFile >> order[i].total.dollars >> order[i].total.cents;
        inFile >> order[i].ordDate.month >> decimal >> order[i].ordDate.day >> decimal >> order[i].ordDate.year;
    }

    inFile.close();

    //printHeading("Orders", 60);

    displayInFileO(order, x);

};

bool Orders::compareDateHP(){


    return true;
};

void Orders::displayInFileO(Orders order[], int x){

   cout << setw(10) << setfill(' ') << "Customer Name" << " | "
         << "Item Name" << "  | "
         << "#Boxes" << "  | "
         << "Cost" << "  | "
         << "Order Date" << endl;

    //printHorizontalLine(60,'-');

    for(int i = 0; i < x; i++){
        cout << left << setw(10) << order[i].nameOrd << "    | "
             << left << setw(10) << order[i].nameItem << " | "
             << right << setw(2) << setfill('0') << order[i].numBox << "      | "
             << left << setw(4) << setfill('0') << order[i].total.dollars << "." << order[i].total.cents<< " | "
             << right << setw(2) << setfill('0') << order[i].ordDate.month <<":" << setw(2) << setfill('0')
                                 << order[i].ordDate.day <<":" << setw(2) << setfill('0') << order[i].ordDate.year << " "
             << setfill(' ') << endl;
    }
};
void Shipments::getInFileS(Shipments shipment[], int x, ifstream& inFile){

     char decimal;

    for(int i = 0; i < x; i++){
        inFile >> shipment[i].food;
        inFile >> shipment[i].expDate.month >> decimal >> shipment[i].expDate.day >> decimal >> shipment[i].expDate.year;
        inFile >> shipment[i].sizeBox.length >> decimal >> shipment[i].sizeBox.width >> decimal >> shipment[i].sizeBox.height;
        inFile >> shipment[i].weight;
        inFile >> shipment[i].bStorageM;
        inFile >> shipment[i].recDate.month >> decimal >> shipment[i].recDate.day >> decimal >> shipment[i].recDate.year;
        inFile >> shipment[i].price.dollars >> decimal >> shipment[i].price.cents;
    }
    inFile.close();

    //printHeading("Shipments", 80);

    displayInFileS(shipment,x);

};

bool Shipments::compareEDate(){

    return true;
};

void Shipments::displayInFileS(Shipments shipment[], int x){

    cout << setw(10) << "Food Item" << "  | "
        << "Exp Date " << "  | "
        << "Box Size" << "  | "
        << "Weight" << " | "
        << "Storage" << " | "
        << "Received date" << " | "
        << "Price" << endl;

    //printHorizontalLine(80,'-');

    for(int i = 0; i < x; i++){
        cout << left << setw(9) << shipment[i].food << "   | "
             << right <<setw(2) << setfill('0') << shipment[i].expDate.month <<":" << setw(2) << setfill('0')
                      << shipment[i].expDate.day <<":" << setw(2) << setfill('0') << shipment[i].expDate.year << " | "
             << right <<setw(2) << setfill('0') << shipment[i].sizeBox.length <<":"<< setw(2) << setfill('0')
                      << shipment[i].sizeBox.width << ":" << setw(2) << setfill('0') <<shipment[i].sizeBox.height << "  | "
             << right <<setw(2) << shipment[i].weight << "     | "
             << right <<shipment[i].bStorageM << "       | "
             << right <<setw(2) << setfill('0') << shipment[i].recDate.month <<":" << setw(2) << setfill('0')
                      << shipment[i].recDate.day <<":" << setw(2) << setfill('0') << shipment[i].recDate.year << "    | "
             << right << fixed << setprecision(2) << setfill('0') << shipment[i].price.dollars << "." << shipment[i].price.cents<< " "
             << setfill(' ') << endl;
       cout.unsetf(ios_base::fixed);
    }
};

/// int main!

int main(){

    int x = 0;
    ifstream oFile;
    ifstream sFile;
    oFile.open("Orders.txt");
    sFile.open("Shipments.txt");

      if (!oFile)
    {
        cout << "The Orders input file does not exist. Program terminates!" << endl;
        return 1;
    }
    if (!sFile)
    {
        cout << "The Shipments input file does not exist. Program terminates!" << endl;
        return 1;
    }

    oFile >> x;
    sFile >> x;

    Shipments shipment[x];
    Orders order[x];

    gship.etInFileS(shipment, x, sFile);
    getInFileO(order, x, oFile);

    return 0;
}