Cant create array of objects in c++ - c++

Question

#include <iostream>
using namespace std;
class Bank
{
private:
char account_holder[50];
int accnum;
int balance;
int dep_amount;
int with_amount;
public:
void getdata();
void putdata();
void deposit();
void withdraw();
};
void Bank::getdata()
{
cout << "Enter the account holders name : " << endl;
cin >> account_holder;
cout << "Enter the account number : " << endl;
cin >> accnum;
cout << "Enter the balance in your account : " << endl;
cin >> balance;
}
void Bank::putdata()
{
cout << "The account holders name is : " << account_holder << endl;
cout << "The account number is : " << accnum << endl;
cout << "The balance in your account is : " << balance << endl;
cout << endl;
}
void Bank::deposit()
{
cout << "Enter the amount to be deposited : " << endl;
cin >> dep_amount;
balance = balance + dep_amount;
cout << "Your current balance is : " << balance << endl;
}
void Bank::withdraw()
{
cout << "Enter the amount to be withdrawn : " << endl;
cin >> with_amount;
balance = balance - with_amount;
cout << "Your current balance is : " << balance << endl;
}
int main(){
Bank ram[5];
int ch, a, n, acc;
cout << "How you account holders you want to add : " << endl;
cin >> n;
do
{
cout << "Enter 1.To insert data" << endl;
cout << "Enter 2.To display data" << endl;
cout << "Enter 3.To deposit amount" << endl;
cout << "Enter 4.To withdraw amount" << endl;
cout << "Enter your choice : " << endl;
cin >> ch;
switch (ch)
{
case 1:
for (int i = 0; i < n;i++)
ram[i].getdata();
break;
case 2:
for (int i = 0; i < n; i++)
ram[i].putdata();
break;
case 3:
cout << "Enter the account you want to deposit money into " << endl;
cin >> acc;
for (int i = 0; i < n; i++)
ram[acc].deposit();
break;
case 4:
for (int i = 0; i < n; i++)
ram[i].withdraw();
break;
}
cout << "Enter 6. To Continue" << endl;
cin >> a;
} while (a == 6);
return 0;
}
I am using this code and my problem is that when I want to deposit or withdraw some amount,I want to take account number from user and then deposit/withdraw amount from that object only. How can I enter that object using account number taken from user? Please Help.

Answer 1

Unfortunately you have a few problems with your code and your logic. Let us address them one by one:
1- You are using a char array to keep the account holder name. If you are programming C++ you should be using std::string in almost all situations.
2- You are using unconventional names for your public methods in Bank and this is a bad habit at best.
More specifically, getdata() is a poor method name because mehtods that start with "get" should generally be reserved for methods that return a single field that belongs to the class instance. For example int getAccountNumber()
your getdata() should be fillInData() follow me?
3- You are using an array of Bank in your main in order to hold the number of accounts. While this is possible, it is far from ideal. You should strive to use std::vector when it makes sense (like here). Why is a naked array bad? because if you use an array the size of the array has to be known at compile time, which means you can not increase the number of accounts when the program is running. If you declare a big array on the stack, you may have a lot of space but you are wasting precious stack space.
4- The logic you have employed for your "input loop" is messy and hard to navigate. The design can be improved significantly to improve readability and maintainability of code. Consider the fact that you declare and read int n; but you never use it in the program.
5- Compile time errors from undeclared variables like i
6- Logically and semantically incorrect program behaviour: you iterate through a for loop of all records and withdraw/deposit in ALL records, instead of selecting the one you need.
7- No bounds checking of any kind. Asking for bad things to happen.
I am giving you a minimally adjusted code that makes sense. Note that this is still not the ideal way to accomplish this task but at least it does not have syntax and semantic errors:
int Bank::getAccountNumber()
{
return this->accnum;
}
int getIndexByAccountNumber(Bank allAccounts[], int size, int accountNumber) //returns index or -1 in case account number is not found
{
for(int i=0; i<size; ++i)
{
if (allAccounts[i].getAccountNumber()==accountNumber) return i;
}
return -1;
}
int main(){
const int NumberOfAccounts=5;
Bank ram[NumberOfAccounts];
int nextIndex=0;
int ch, a, acc;
while(true)
{
cout << "Enter 1.To insert data for a new account" << endl;
cout << "Enter 2.To display data of all existing accounts" << endl;
cout << "Enter 3.To deposit to an existing account" << endl;
cout << "Enter 4.To withdraw from an existing account" << endl;
cout << "Enter 5.To terminate program" << endl;
cout << "Enter your choice : " << endl;
cin >> ch;
if(ch==1)
{
if(nextIndex>=NumberOfAccounts)
{
cout<<"error: you have space for only "<<NumberOfAccounts<<" accounts! terminating program";
break;//breaks out of while loop
}
ram[nextIndex].getdata();//gets all fields for the account
nextIndex++;
}
else if(ch==2)
{
cout << "showing information for all accounts: " << endl;
for (int i = 0; i < nextIndex; i++) ram[i].putdata();
cout<<"\n\n";
}
else if(ch==3)
{
cout << "Enter the account you want to deposit money into " << endl;
cin >> acc;
int index = getIndexByAccountNumber(ram,NumberOfAccounts,acc);
if(index==-1)
{
cout<<"the account number you entered could not be found, terminating program!\n";
break;//breaks out of while loop
}
ram[index].deposit();
}
else if(ch==4)
{
cout << "Enter the account you want to withdraw from " << endl;
cin >> acc;
int index= getIndexByAccountNumber(ram,NumberOfAccounts,acc);
if(index==-1)
{
cout<<"the account number you entered could not be found, terminating program!\n";
break;//breaks out of while loop
}
ram[index].withdraw();
}
else if(ch==5)
{
break;
}
else
{
cout<<"you entered invalid choice\n";
}
}//end of while loop
return 0;
}

Answer 2

cout << "Enter the account you want to deposit money into " << endl;
cin >> acc;
for (int i = 0; i < n; i++)
ram[acc].deposit();
break;
Here is your problem - wrong index variable. Try "i"

Answer 3

In your case 3 you use a different iterator than the rest. Is this by design or what? I am missing the purpose of using acc instead of i. This might be your problem, unless I am overlooking your purpose for using it.