include Inheritance and Friend Functions and template

[Hesam918]

hello! i have this code and i need to include some extra topic on it.
inheritance
friend function
template
Aggregation (Composition)
help me pls..

 #include<iostream>
#include<fstream>
#include<cctype>
#include<iomanip>
using namespace std;

class account
{
	int acno;
	char name[50];
	int deposit;
	char type;
public:
	void create_account();
	void show_account() const;
	void modify();
	void dep(int);
	void draw(int);
	void report() const;
	int retacno() const;
	int retdeposit() const;
	char rettype() const;
};
        

void account::create_account()
{
	cout << "\nEnter The account No. :";
	cin >> acno;
	cout << "\n\nEnter The Name of The account Holder : ";
	cin.ignore();
	cin.getline(name, 50);
	cout << "\nEnter Type of The account (TL/S) : ";
	cin >> type;
	type = toupper(type);
	cout << "\nEnter The Initial amount(>=500 for Saving and >=1000 for current ) : ";
	cin >> deposit;
	cout << "\n\n\nAccount Created..";
}

void account::show_account() const
{
	cout << "\nAccount No. : " << acno;
	cout << "\nAccount Holder Name : ";
	cout << name;
	cout << "\nType of Account : " << type;
	cout << "\nBalance amount : " << deposit;
}


void account::modify()
{
	cout << "\nAccount No. : " << acno;
	cout << "\nModify Account Holder Name : ";
	cin.ignore();
	cin.getline(name, 50);
	cout << "\nModify Type of Account : ";
	cin >> type;
	type = toupper(type);
	cout << "\nModify Balance amount : ";
	cin >> deposit;
}


void account::dep(int x)
{
	deposit += x;
}

void account::draw(int x)
{
	deposit -= x;
}

void account::report() const
{
	cout << acno << setw(10) << " " << name << setw(10) << " " << type << setw(6) << deposit << endl;
}


int account::retacno() const
{
	return acno;
}

int account::retdeposit() const
{
	return deposit;
}

char account::rettype() const
{
	return type;
}


void write_account();	
void display_sp(int);	
void modify_account(int);	
void delete_account(int);	
void display_all();		
void deposit_withdraw(int, int); 



int main()
{
	char ch;
	int num;
	do
	{
		system("cls");
		cout << "\n\n\n\tMAIN MENU";
		cout << "\n\n\t01. NEW ACCOUNT";
		cout << "\n\n\t02. DEPOSIT AMOUNT";
		cout << "\n\n\t03. WITHDRAW AMOUNT";
		cout << "\n\n\t04. BALANCE ENQUIRY";
		cout << "\n\n\t05. ALL ACCOUNT HOLDER LIST";
		cout << "\n\n\t06. CLOSE AN ACCOUNT";
		cout << "\n\n\t07. MODIFY AN ACCOUNT";
		cout << "\n\n\t08. EXIT";
		cout << "\n\n\tSelect Your Option (1-8) ";
		cin >> ch;
		system("cls");
		switch (ch)
		{
		case '1':
			write_account();
			break;
		case '2':
			cout << "\n\n\tEnter The account No. : "; cin >> num;
			deposit_withdraw(num, 1);
			break;
		case '3':
			cout << "\n\n\tEnter The account No. : "; cin >> num;
			deposit_withdraw(num, 2);
			break;
		case '4':
			cout << "\n\n\tEnter The account No. : "; cin >> num;
			display_sp(num);
			break;
		case '5':
			display_all();
			break;
		case '6':
			cout << "\n\n\tEnter The account No. : "; cin >> num;
			delete_account(num);
			break;
		case '7':
			cout << "\n\n\tEnter The account No. : "; cin >> num;
			modify_account(num);
			break;
		case '8':
			cout << "\n\n\tThanks for using bank managemnt system";
			break;
		default:cout << "\a";
		}
		cin.ignore();
		cin.get();
	} while (ch != '8');
	return 0;
}




void write_account()
{
	account ac;
	ofstream outFile;
	outFile.open("account.dat", ios::binary | ios::app);
	ac.create_account();
	outFile.write(reinterpret_cast<char *> (&ac), sizeof(account));
	outFile.close();
}



void display_sp(int n)
{
	account ac;
	bool flag = false;
	ifstream inFile;
	inFile.open("account.dat", ios::binary);
	if (!inFile)
	{
		cout << "File could not be open !! Press any Key...";
		return;
	}
	cout << "\nBALANCE DETAILS\n";

	while (inFile.read(reinterpret_cast<char *> (&ac), sizeof(account)))
	{
		if (ac.retacno() == n)
		{
			ac.show_account();
			flag = true;
		}
	}
	inFile.close();
	if (flag == false)
		cout << "\n\nAccount number does not exist";
}



void modify_account(int n)
{
	bool found = false;
	account ac;
	fstream File;
	File.open("account.dat", ios::binary | ios::in | ios::out);
	if (!File)
	{
		cout << "File could not be open !! Press any Key...";
		return;
	}
	while (!File.eof() && found == false)
	{
		File.read(reinterpret_cast<char *> (&ac), sizeof(account));
		if (ac.retacno() == n)
		{
			ac.show_account();
			cout << "\n\nEnter The New Details of account" << endl;
			ac.modify();
			int pos = (-1)*static_cast<int>(sizeof(account));
			File.seekp(pos, ios::cur);
			File.write(reinterpret_cast<char *> (&ac), sizeof(account));
			cout << "\n\n\t Record Updated";
			found = true;
		}
	}
	File.close();
	if (found == false)
		cout << "\n\n Record Not Found ";
}




void delete_account(int n)
{
	account ac;
	ifstream inFile;
	ofstream outFile;
	inFile.open("account.dat", ios::binary);
	if (!inFile)
	{
		cout << "File could not be open !! Press any Key...";
		return;
	}
	outFile.open("Temp.dat", ios::binary);
	inFile.seekg(0, ios::beg);
	while (inFile.read(reinterpret_cast<char *> (&ac), sizeof(account)))
	{
		if (ac.retacno() != n)
		{
			outFile.write(reinterpret_cast<char *> (&ac), sizeof(account));
		}
	}
	inFile.close();
	outFile.close();
	remove("account.dat");
	rename("Temp.dat", "account.dat");
	cout << "\n\n\tRecord Deleted ..";
}


void display_all()
{
	account ac;
	ifstream inFile;
	inFile.open("account.dat", ios::binary);
	if (!inFile)
	{
		cout << "File could not be open !! Press any Key...";
		return;
	}
	cout << "\n\n\t\tACCOUNT HOLDER LIST\n\n";
	cout << "====================================================\n";
	cout << "A/c no.      NAME           Type  Balance\n";
	cout << "====================================================\n";
	while (inFile.read(reinterpret_cast<char *> (&ac), sizeof(account)))
	{
		ac.report();
	}
	inFile.close();
}



void deposit_withdraw(int n, int option)
{
	int amt;
	bool found = false;
	account ac;
	fstream File;
	File.open("account.dat", ios::binary | ios::in | ios::out);
	if (!File)
	{
		cout << "File could not be open !! Press any Key...";
		return;
	}
	while (!File.eof() && found == false)
	{
		File.read(reinterpret_cast<char *> (&ac), sizeof(account));
		if (ac.retacno() == n)
		{
			ac.show_account();
			if (option == 1)
			{
				cout << "\n\n\tTO DEPOSITE AMOUNT ";
				cout << "\n\nEnter The amount to be deposited";
				cin >> amt;
				ac.dep(amt);
			}
			if (option == 2)
			{
				cout << "\n\n\tTO WITHDRAW AMOUNT ";
				cout << "\n\nEnter The amount to be withdraw";
				cin >> amt;
				int bal = ac.retdeposit() - amt;
				if ((bal<500 && ac.rettype() == 'S') || (bal<1000 && ac.rettype() == 'C'))
					cout << "Insufficience balance";
				else
					ac.draw(amt);
			}
			int pos = (-1)*static_cast<int>(sizeof(ac));
			File.seekp(pos, ios::cur);
			File.write(reinterpret_cast<char *> (&ac), sizeof(account));
			cout << "\n\n\t Record Updated";
			found = true;
		}
	}
	File.close();
	if (found == false)
		cout << "\n\n Record Not Found ";
}

[MikeyBoy]

It should be fairly obvious how you add inheritence to the program, as you have two different types of account that will share some common behaviour, but will also need to have specialised behaviour.

[ne555]

void modify();
however, noyice that an account may modify its type (see strategy)

if(not ac.draw(amt))
   cout << "Error\n";

the restriction may be resolved with polymorphism

[icy1]

(side note: it's a good idea to capitalize classes and global methods, and to be honest, member methods, especially if you're using the full std namespace. One of these days you'll conflict with the purposely-lowercase stuff in there)

Inheritance - make a simple base class

Did you want Aggregation specifically or any Composition? You need to be specific about if the stuff owned needs to die or not
https://en.wikipedia.org/wiki/Object_composition#Aggregation
Account could own one or more of SomeOtherClass.

friend function - simple and useful would be to make an output stream a friend
friend std::ostream & operator<<(std::ostream &os, const Account& a);
and then define this method in the global scope. Stringifying it in this way will be easy because the private vars are accessible.

Template - could template-ize your Deposit method to take T x instead of int x.

[doug4]

(side note: it's a good idea to capitalize classes and global methods, and to be honest, member methods,

Are you trying to start a religious war here?

I happen to agree with capitalizing classes, but not methods (global or member). I also prefer camelCaps rather than separated_with_underscores, but I don't want to start arguments about that. I also love where the @OP placed the opening curly braces, but many here will cringe that they are not at the end of the previous lines.

The important thing is to have a consistent style while learning the basics of programming. There are a lot of "good ideas" out there, many of which contradict one another. When one joins a company, he/she will have a dictated style that should be followed. Until then, developing a consistent style is more important than the "right" style.

especially if you're using the full std namespace. One of these days you'll conflict with the purposely-lowercase stuff in there)

Which brings us to whether someone should use the using namespace std; construct in his/her code. This is the reason it is frowned on by many on this board.

[icy1]

@doug4 I was definitely influenced by the Google Style Guide, e.g. the sections starting wtih Type Names https://google.github.io/styleguide/cppguide.html#Type_Names . A lot of their rules make sense to me, like the preference for PascalCase, the variant of CamelCase where the first letter is capitalized. snake_case is for public variables (I believe for protected too), and snake_case_ with trailing underscore for private vars always made sense to me.

Naming stuff like "camelCase" with lowercase first letter makes me think of old Microsoft or Java code, but I dislike both -- Microsoft conventions overall are quite strange (see: "iNum"), and Java is not C++.

I do change at least a few things from the guide:
- I tend to use 4 spaces for C++ indentation while the preference there is 2 (I used to use 2)
- (related) I don't feel badly about going over 80 column width on occasion
- I prefer braces on their own lines
- my source files are usually named Blah.cpp rather than blah.cc

Oh, and my take on using namespace std; is that it's totally fine in the one-file demo code that contains main() (which fits the bill for the majority of responses here). Occasionally I'd reply with multi-file project code, where I'd usually only do that in the main.cpp file.

[Ganado]

Death to Google Style Guide! I declare an intifada against it!

There, holy war started.