ostream operator<< not working properly

Question

ostream issues My ostream operator << seems not to be working or something else

Answer 1

There is a logic error in the function Customer::getHash. That may not solve your problem but it should be fixed anyway.

int Customer::getHash(int hash)
{
    string key = getLastname();
    cout<<"key: "<<key<<endl;
    // getFirstname();
    //  getID();
    int i = 0;
    // int j = 0;
    // int k = 0;
    for (i = 0; i < key.length(); i++)
    {
        i += (int)key[i]; // Problem.
                          // At this time, i may be greater than key.length().
    }
   // getFirstname();
   // getID();
   return  i = i % hash;

}

You can fix it by using a different variable to keep the temporary hash value.

int Customer::getHash(int hash)
{
    string key = getLastname();
    cout<<"key: "<<key<<endl;
    int tempHash = 0;
    int i = 0;
    for (i = 0; i < key.length(); i++)
    {
        tempHash += (int)key[i];
    }
   return  tempHash % hash;    
}

Update

In your posted code, you have commented out the return statement in the function

istream &operator >> (istream &in, Customer &obj)

As a side effect, the behavior of

 while (inputFile >> newCustomer)

is undefined.

Uncomment the line

//return in;

in the function. That will fix another error. Hopefully that's the last one.

Update 2

You are reading too much information in the while loop.

 // This line reads all the information of one customer
 while (inputFile >> newCustomer)
 {
    //inputFile >> newCustomer;
    string lastname;

    // PROBLEM
    // Now you are reading data corresponding to the next customer.

    getline (inputFile, lastname, ' ');
    while (inputFile.peek() == ' ')
       inputFile.get();

    string firstname;
    getline (inputFile, firstname, ' ');
    while (inputFile.peek() == ' ')
       inputFile.get();

    string id;
    getline (inputFile, id);

    buildCustomerList(cHeadPtr, cTailPtr, lastname, firstname, id);
    customer.insert(newCustomer);
    //cout<<lastname<<endl;
    //cout<<firstname<<endl;
    //cout<<id<<endl;
 }

Change it to:

 while (inputFile >> newCustomer)
 {
    string lastname = newCustomer.getLastname();
    string firstname = newCustomer.getFirstname();
    string id = newCustomer.getID();

    buildCustomerList(cHeadPtr, cTailPtr, lastname, firstname, id);
    customer.insert(newCustomer);
 }