mainprog.cpp

这是学习c++的一些编译过的示例,经典的,希望对你有用.

			// Add a single student record
			cout << endl << "Adding Student record." << endl;
			add_person(true); 
			break;
		default: 
			cout << endl << "Not a valid option.  Try again." << endl;
			break;
		}
	}
	catch(create_ex* pEx) {
		cout << "Error encountered during record creation. Error message was:" << endl;
		cout << pEx->what() << endl;
	}
}

/* 
******************************************************
*	Function:	add_person
*	return:		void
*	parameters:	none
*
*	Description:
*	This function will determine what type of record will be 
*	added to the Container 'persons' (i.e. either a Student record
*	or a Teacher record).
*
******************************************************
*/

void add_person(bool is_student) {
	// Add the record to the appropriate container.  
	// The type of record (i.e. either "Student" or "Teacher") 
	// is determined by the variable is_student.
		
	if (!is_student) {
		// Create a Teacher object on the heap (i.e. allocate the memory)
		// then add it to the Container 'persons'

		Teacher* tempTeacher = new Teacher();
		
		// Uncomment the next line to test the exception-handling
		// tempTeacher = 0;

		if (!tempTeacher)
			throw new create_ex("Failed to create teacher");

		// Get the data for the teacher object
		tempTeacher->setup();

		persons.push_back(tempTeacher);
	}
	else {
		// Create a Student object on the heap (i.e. allocate the memory)
		// then add it to the Container 'persons'

		Student *tempStudent = new Student();
		
		if (!tempStudent)
			throw new create_ex("Failed to create student");

		// Get the data for the teacher object
		tempStudent->setup();

		persons.push_back(tempStudent);
	}
}

/* 
******************************************************
*	Function:	search_record
*	return:		void
*	parameters:	none
*
*	Description:
*	This function will prompt the user to enter a 
*	surname, then call the function to search the 
*	existing records.	
*
******************************************************
*/

void search_record() {
	string surname;
	char option;

	do	{
		// Display the Search Surname Menu
		cout << endl << "SEARCH SURNAME. " << endl;
		cout << endl << "---------------" << endl;

		cout << endl <<"Enter the Surname to Search for." << endl;
		cin >> surname;

		// Search the records for the user input surname.
		search_surname(surname);

		cout << endl << "Do you want to continue searching [Y/N]? " << endl;

    cin >> option;
    option = static_cast<char>(std::toupper(option));
	
	}while (option != 'N'); // Continue searching until user enters 'N' or 'n'
}

/* 
******************************************************
*	Function:	search_surname
*	return:		void
*	parameters:	const string &surname
*
*	Description:
*	This function will search the existing records 
*	to find which record matches the user entered
*	Surname.	
*
******************************************************
*/

void search_surname(const string &surname) {
	unsigned int i = 0;

	// Loop around all student and teacher records for a match on 
	// the surname.
	for (i = 0; i < persons.size(); i++) {
		pPerson = persons[i];
	
		// Compare the surname field of the record at index i 
		// with the user input record.
		// *** implement match_surname() in Person, which returns bool ***
		if ((surname.compare(pPerson->get_surname()) == 0)) {
			cout << endl << "Record # " << i + 1 << endl;

			pPerson->display_info();
			pPerson->display_other_info();

			return;
		}
	}

	// Let the user know if the record is not found.
	cout << endl << "The Surname " << surname << " was not found." << endl;
}


/* 
******************************************************
*	Function:	display_all
*	return:		void
*	parameters:	bool do_teachers, bool do_students
*
*	Description:
*	This function will display the current records.  If
*	the parameter do_teachers is true, then all 
*	teachers will be displayed.  If the parameter 
*	do_students is true, then all students will be 
*	displayed.		
*
******************************************************
*/

void display_all(bool do_teachers, bool do_students) {
	int i = 0;

	// Display a header outlining which records will be output
	// to the screen.

	if (do_teachers && do_students)
		cout << endl << "displaying All Records." << endl;
	else if (do_teachers)
		cout << endl << "displaying All Teacher Records." << endl;
	else if (do_students)
		cout << endl << "displaying All Student Records." << endl;
	
	// Loop around all records in Container 'persons'.
	for (i = 0; i < persons.size(); i++) {
		pPerson = persons[i];

		// Determine whether or not the current record is to be displayed.

		if ( (do_teachers && (typeid(*pPerson) == typeid(Teacher))) ||
			 (do_students && (typeid(*pPerson) == typeid(Student))) ) {
			pPerson->display_info();
			pPerson->display_other_info();

			cout << endl << " Press ENTER to continue..." << endl;
			cin.get();
			cout << endl;
		}
	}

	cout << endl << "Returning to the display Record System Menu." << endl;
}


/* 
******************************************************
*	Function:	save_records 
*	return:		void
*	parameters:	none
*
*	Description:
*	This function will save the current list of records to
* a disk file
*
******************************************************
*/

void save_records() {
	string fn;

	// Basic sanity check
	if (persons.size() == 0) {
		cout << "There are no records to save!" << endl;
		return;
	}

	// get filename and open file
	cout << endl <<"Enter the filename (no extension):" << endl;
	cin >> fn;

	// verify it doesn't contain a '.', then add extension
	if (fn.find('.') != string::npos) {
		cout << "Can't have a '.' in a filename!";
		return;
	}
	fn += ".ih";

	// open file
	std::ofstream of(fn.c_str());
	if (!of.good()) {
		cout << "Error opening file" << endl;
		return;
	}

	// write header lines
	of << "Ivor Horton\'s ANSI C++ Database File" << endl;
	of << persons.size() << endl;

	// loop over records, writing each one out.
	// We need to say what sort of record each one is first, and then write the data
	// one line at a time
	for (int i = 0; i < persons.size(); i++) {
		pPerson = persons[i];
		if (typeid(*pPerson) == typeid(Teacher))
			of << "**Teacher" << endl;
		else
			of << "**Student" << endl;

		pPerson->dump_info(of);
	}

	// close file
	of.close();
}


/* 
******************************************************
*	Function:	load_records
*	return:		void
*	parameters:	none
*
*	Description:
*	This function will load a set of records from a file
*
******************************************************
*/

void load_records() {
	string fn;    // filename
	string temp;  // working string

	// get filename and open file
	cout << endl <<"Enter the filename (no extension):" << endl;
	cin >> fn;

	// verify it doesn't contain a '.', then add extension
	if (fn.find('.') != string::npos) {
		cout << "Can't have a '.' in a filename!";
		return;
	}
	fn += ".ih";

  std::ifstream is(fn.c_str());
	if (!is.good()) {
		cout << "Error opening file" << endl;
		return;
	}

	// verify header line
  std::getline(is, temp, '\n');

	if (temp != "Ivor Horton\'s ANSI C++ Database File") {
		cout << "This doesn't seem to be a database file..." << endl;
		return;
	}

	// next line tells us how many records there are
	int nVals;
	is >> nVals;
	cout << "The file contains " << nVals << " records" << endl;

	// loop over records
	for (int i=0; i<nVals; i++) {
		// See what type of object we're reading, and create the appropriate type
    std::ws(is);     // Ignore initial whitespace
		getline(is, temp, '\n');
		if (temp == "**Teacher") {
			cout << "> teacher" << endl;
			pPerson = new Teacher();
		}
		else if (temp == "**Student") {
			cout << "> student" << endl;
			pPerson = new Student();
		}
		else {
			cout << "error! unknown record type" << endl;
			return;
		}

		// Get the object to read in its data
		pPerson->load_info(is);

		// Add it to the deque
		persons.push_back(pPerson);
	}
}

void record_report() {
	cout << endl << "There are " << persons.size() << " records in the list" << endl;

	int nTeachers = 0;
	int nStudents = 0;
	for (unsigned int i = 0; i < persons.size(); i++) {
		pPerson = persons[i];
		if (typeid(*pPerson) == typeid(Teacher))
			nTeachers++;
		else
			nStudents++;
	}
	cout << "Of these, " << nTeachers << " are teachers and " << nStudents << " are students" << endl;
}