Working with Classes - Invalid allocation size - c++

Question

i have homework, but it is not working. Best i can guess as to why it is not working is an auto breakpoint to vs2013 which displays this in the output box.
HEAP[hw2_ccc.exe]: Invalid allocation size - 10 (exceeded fffdefff)
First-chance exception at 0x000007FEFD9D940D in hw2_ccc.exe: Microsoft C++ exception: std::bad_alloc at memory location 0x000000000012F350.
HEAP[hw2_ccc.exe]: Invalid allocation size - 1 (exceeded fffdefff)
First-chance exception at 0x000007FEFD9D940D in hw2_ccc.exe: Microsoft C++ exception: std::bad_alloc at memory location 0x000000000012CE40.
First-chance exception at 0x000007FEFD9D940D in hw2_ccc.exe: Microsoft C++ exception: [rethrow] at memory location 0x0000000000000000.
First-chance exception at 0x000007FEFD9D940D in hw2_ccc.exe: Microsoft C++ exception: std::bad_alloc at memory location 0x000000000012CE40.
A buffer overrun has occurred in hw2_ccc.exe which has corrupted the program's internal state.
Here is my code:
bankAccount.h
#ifndef H_bankAccount
#define H_bankAccount
#include <string>
#include <iostream>
using namespace std;
class bankAccount
{
public:
void setAccountName(string holderName);
void setAccountNumber(int accountNumber);
void setInterestRate(double interestRate);
void setAccountType(string accountType);
void depositBalance(double deposit);
void withdrawBalance(double withdraw);
void printAccountInformation();
void newAccount(string holderName, int accountNumber, string accountType, double interestRate);
string getAccountName();
bankAccount();
~bankAccount();
private:
string holderName;
int accountNumber;
string accountType;
double balance;
double interestRate;
};
#endif
bankAccount.cpp
#include "bankAccount.h"
using namespace std;
bankAccount::bankAccount()
{
}
bankAccount::~bankAccount()
{
}
void bankAccount::newAccount(string holderName, int accountNumber, string accountType, double interestRate)
{
setAccountName(holderName);
setAccountNumber(accountNumber);
setAccountType(accountType);
setInterestRate(interestRate);
}
void bankAccount::setAccountName(string holderName)
{
bankAccount::holderName = holderName;
}
void bankAccount::setAccountNumber(int accountNumber)
{
bankAccount::accountNumber = accountNumber;
}
void bankAccount::setAccountType(string accountType)
{
bankAccount::accountType = accountType;
}
void bankAccount::setInterestRate(double interestRate)
{
bankAccount::interestRate = interestRate;
}
void bankAccount::depositBalance(double deposit)
{
bankAccount::balance += deposit;
}
void bankAccount::withdrawBalance(double withdraw)
{
bankAccount::balance -= withdraw;
}
void bankAccount::printAccountInformation()
{
cout << "Account Name: " << bankAccount::holderName << endl;
cout << "Account Type: " << bankAccount::accountType << endl;
cout << "Account Number: " << bankAccount::accountNumber << endl;
cout << "Account Interest Rate: " << bankAccount::interestRate << endl;
cout << "Account Balance :" << bankAccount::balance << endl;
}
string bankAccount::getAccountName()
{
return holderName;
}
main.cpp
#include "bankAccount.h"
using namespace std;
int randAccountNum();
string randAccountType();
int interestRate(string accountType);
bool printAccount(bankAccount accounts[10]);
int main()
{
bankAccount account[10];
string accountNames[10] = { "Bob", "Jack", "Billy", "James", "Kathy", "John", "Jenny", "Penny", "Sue", "Louis" };
string accountType;
int accountNumber;
bool prAcc = true;
for (int i = 0; i < sizeof(account); i++)
{
accountType = randAccountType();
accountNumber = randAccountNum();
account[i].newAccount(accountNames[i], accountNumber, accountType, interestRate(accountType));
}
while (prAcc)
{
prAcc = printAccount(account);
}
system("pause");
return 0;
}
int randAccountNum()
{
int num = rand() % 1000 + 1;
return num;
}
string randAccountType()
{
string str;
int num = rand() % 2 + 1;
if (num = 1)
{
str = "Savings";
}
else {
str = "Checking";
}
return str;
}
int interestRate(string accountType)
{
int ir;
if (accountType == "Savings")
{
ir = 2;
}
else {
ir = 4;
}
return ir;
}
bool printAccount(bankAccount accounts[10])
{
string cont;
bool contL = true;
string accountName;
cout << "Enter account name: ";
cin >> accountName;
cout << endl;
for (int i = 0; i < sizeof(accounts); i++)
{
if (accounts[i].getAccountName() == accountName)
{
accounts[i].printAccountInformation();
}
}
while (contL)
{
cout << "Enter another name? (Yes/No): ";
cin >> cont;
if (cont == "Yes")
return true;
else if (cont == "No")
return false;
else
cout << "Invalid. Please enter Yes or No" << endl;
}
}

Answer 1

Change this statement
for (int i = 0; i < sizeof(account); i++)
to
for (int i = 0; i < sizeof(account) / sizeof(*account); i++)
Also there is error in function
bool printAccount(bankAccount accounts[10]);
In this statement
for (int i = 0; i < sizeof(accounts); i++)
sizeof(accounts) is equal to sizeof( bankAccount * )
You have to declare a second parameter for the size of the array passed to the function.
Take into account that you could use objects of type std::array unstead of the arrays. In this case there would not be such problems with the sizes of the arrays.

Answer 2

In your code:
bankAccount account[10];
...
for (int i = 0; i < sizeof(account); i++)
You have a problem in loop iteration (in particular, in the upper bound).
Your account array contains 10 instances of your bankAccount class.
It's clear that your intent is to iterate through all the array items. For that to work correctly, valid values for the i loop index are 0, 1, 2, 3, ..., 9. So, this would work if sizeof(account) returned 10 (in fact, you use the < operator, to exclude the upper limit of 10, and just stopping one value before, at 9, which is correct).
The problem is that sizeof(account) does return the size in bytes of the account array. This is equivalent to 10 * sizeof(bankAccount), where again sizeof(bankAccount) returns the size in bytes of your bankAccount class. Assuming that your bankAccount class' size is e.g. 40 bytes, then sizeof(account) becomes 10 * 40, i.e. 400 bytes.
So, in this case, in your for loop, your index spans values 0,1,2,3,4,...9, 10,11,12,...399: the values in bold are valid, the next ones are not!
You have what is called a buffer overrun, which is clearly stated in the VC++ compiler's error message:
[...] A buffer overrun has occurred
To fix that problem, you have several options.
For example, to get the proper item count, you can divide the total size (in bytes) of the array, by the size of one of its elements, e.g. the first one, at index 0:
// Count of items in the 'account' array
const int accountCount = sizeof(account) / sizeof(account[0]);
for (int i = 0; i < accountCount; i++)
...
Another option is to use a more modern C++ approach, e.g. using C++11's std::array:
#include <array> // for std::array
...
// Define an array of 10 bankAccount's
std::array<bankAccount, 10> account;
// Note that account.size() is 10!
// i.e., this is the size in *element count* (not in bytes, like sizeof()).
for (int i = 0; i < account.size(); i++)
...