employ3.cpp

实用的算法

/*
	employ3.cpp. stream inserters.
 */
#include	"stdio.h"
#include	"stdlib.h"
#include	<iostream.h>
#include	<fstream.h>
#include	<string.h>

class CEmployee
{
public:
    CEmployee (int ID, char *First, char *Last);
	CEmployee ()
    {
        m_EmployeeFirst = NULL;
        m_EmployeeLast = NULL;
    }
	CEmployee (const CEmployee &);
	~CEmployee ();

    int GetID () {return (m_EmployeeID);}
    char *GetFirstName () {return (m_EmployeeFirst);}
    char *GetLastName () {return (m_EmployeeLast);}
	void PutNewName (char *NewFirst, char *NewLast);
    const CEmployee& operator= (const CEmployee &);
    friend ofstream& operator<<(ofstream& stream, CEmployee& c);
    friend ostream& operator<<(ostream& stream, CEmployee& c);
    friend ifstream& operator<<(ifstream& stream, CEmployee& c);
    friend istream& operator<<(istream& stream, CEmployee& c);

private:
	int		m_EmployeeID;
    char    *m_EmployeeFirst;
    char    *m_EmployeeLast;
};

ostream& operator<<(ostream& stream, CEmployee& c)
{
    stream << "First Name: ";
    stream << c.m_EmployeeFirst << endl;
    stream << "Last Name: ";
	stream << c.m_EmployeeLast << endl;
    stream << "ID Number: " << c.m_EmployeeID << endl;
	return (stream);
}

ofstream& operator<<(ofstream& stream, CEmployee& c)
{
    stream << c.m_EmployeeFirst << ',';
    stream << c.m_EmployeeLast << ',';
    stream << c.m_EmployeeID << endl;
    return (stream);
}

istream& operator>>(istream& stream, CEmployee& c)
{
char First[128], Last[128], ID[128];
    cout << "Employee's First Name: ";
    stream >> First;
    cout << "Employee's Last Name: ";
    stream >> Last;
    cout << "Employee's ID Number: ";
    cin >> ID;
    CEmployee temp(atoi (ID), First, Last);
    c = temp;
	return (stream);
}

ifstream& operator>>(ifstream& stream, CEmployee& c)
{
char buf[128];
    stream >> buf;
    char *First = strtok (buf, ",");
    char *Last = strtok (NULL, ",");
    char *ID = strtok (NULL, ",");
    CEmployee temp(atoi (ID), First, Last);
    c = temp;
    return (stream);
}

int main ()
{

CEmployee emp[] =  {
				   CEmployee (1641, "Thomas", "Jefferson"),
				   CEmployee (1802, "George", "Washington"),
				   CEmployee (1732, "John", "Adams"),
				   CEmployee (1752, "Andrew", "Jackson"),
				   CEmployee (2401, "Elsie", "Smith")
				   };
	CEmployee NewEmp;
    ifstream i("employ3.dat", ios::in | ios::out
                              | ios::binary);
    i >> NewEmp;
	cout << NewEmp;
return (0);
	cin >> NewEmp;
	cout << NewEmp;
    CEmployee Emp = emp[0];
    emp[0].PutNewName("Lawrence", "Smith");
	cout << Emp;
    ofstream f("employ3.dat", ios::in | ios::out
                              | ios::binary);
	for (int x = 0; x < 6; ++x)
		f << emp[x];
	f.close ();
//    printf ("%s %s\n", Emp.GetFirstName(), Emp.GetLastName());
//    printf ("%s %s\n", emp[0].GetFirstName(), emp[0].GetLastName());
}

CEmployee::CEmployee (int ID, char *First, char *Last)
{
    m_EmployeeID = ID;
	m_EmployeeFirst = new char [strlen (First) + 1];
    strcpy (m_EmployeeFirst, First);
	m_EmployeeLast = new char [strlen (Last) + 1];
    strcpy (m_EmployeeLast, Last);
}

CEmployee::~CEmployee ()
{
	delete [] m_EmployeeFirst;
	delete [] m_EmployeeLast;
}

void CEmployee::PutNewName (char *NewFirst, char *NewLast)
{
	delete [] m_EmployeeFirst;
	delete [] m_EmployeeLast;
	m_EmployeeFirst = new char [strlen (NewFirst) + 1];
    strcpy (m_EmployeeFirst, NewFirst);
	m_EmployeeLast = new char [strlen (NewLast) + 1];
    strcpy (m_EmployeeLast, NewLast);
}

const CEmployee& CEmployee::operator=(const CEmployee &Old)
{
	delete [] m_EmployeeFirst;
	delete [] m_EmployeeLast;
    m_EmployeeFirst = new char [strlen (Old.m_EmployeeFirst) + 1];
    m_EmployeeLast = new char [strlen (Old.m_EmployeeLast) + 1];
	strcpy (m_EmployeeFirst, Old.m_EmployeeFirst);
	strcpy (m_EmployeeLast, Old.m_EmployeeLast);
	m_EmployeeID = Old.m_EmployeeID;
	return (*this);
}

CEmployee::CEmployee (const CEmployee &Old)
{
    m_EmployeeFirst = new char [strlen (Old.m_EmployeeFirst) + 1];
    m_EmployeeLast = new char [strlen (Old.m_EmployeeLast) + 1];
	strcpy (m_EmployeeFirst, Old.m_EmployeeFirst);
	strcpy (m_EmployeeLast, Old.m_EmployeeLast);
	m_EmployeeID = Old.m_EmployeeID;
}