Your problem lies with the fact that you're trying to give an imaginary variable some data to save. Let me clarify below:
The root of your problem is this line in your current code:
int n = 1;
for(int i = 0; i < n; i++){
bankAccounts[j].setOwnership(); //<-- THIS LINE
std::cout << "You have succsesfully created your bank account!\n\n";
n++;
j++;
break;
}
} else if (st1 == 2) {
or more precisely bankAccounts[j]
Lets look at this in a simpler fashion:
You have an array of lets say int values: int tab[10]. This array has as you can see 10 values aka 10 variables inside it. When using this table, you have to use its name and index of the value/variable however you want to call it you want to use. eg: tab[0] = 3 will set the first element of the arrayto number 3. Now if you try doing this outside the scope of the array (i mean below 0 or higher than the size of the table) youll get an error because you defined the array to have 10 values with indexes from 0 to 9 thus int 10 for array doesnt exist.
Now what you have in your example is an array. arrays, if not used dynamically, have static sizes meaning sizes you cannot change. So if you define int accountNum = 0; and then use it to create array bank bankAccounts[accountNum]; what you're left with is an array of size 0 meaning its empty and you can't change its size during the run of the program. Even if you add to the accountNum anywhere in the code, the array has already been created and the size of it wont change. on a simpler example it would look something like this:
int n = 0;
int tab[n];
No matter what where after the creation of tab we try to change value of n, the tab will always have 0 elements.
Which basically is the same as typing int tab[0];. which also means there is no index in there, not even index 0 that you can use to save data inside. If you change this number accountNum to lets say 1, your program will work without crashing, or at least it did for me in QT environment.
Now onto the solutions. The solution to your problem is to just have something with dynamic sizes preferably to first not have to use global variables and second, to make your code well work. You have a few options to do this. One of the most basic ones is a dynamic array but to do that you'll need to do a little research yourself. The better solution and easier is in my opinions vectors<> which will enable you to do what you're doing in minimalistic amounts of lines of code. What i mean is:
This is your example 1:1 using vectors (which have dynamic sizes)
#include <iostream>
#include <vector> //this is needed. Note that we dont need an AccountNum variable to set size of vector
class bank {
int balance;
std::string ownedBy;
public:
bank()
{
}
void setOwnership() {
balance = 0;
std::cout << "Enter the name of this bank account's owner: \n";
std::cin >> ownedBy;
}
friend std::ostream& operator<<(std::ostream& os, const bank& dt);
};
std::ostream& operator<<(std::ostream& os, const bank& dt)
{
os << dt.balance;
return os;
}
int main() {
int j = 0;
int a;
int st1;
//Array for objects from the bank class
std::vector<bank> bankAccounts; //we create vector of type bank.
// Note that vector size starts at 0
for(;;) {
std::cout << "What would you like to do today?\n";
std::cout << "Enter 1 to create a bank account\n";
std::cout << "Enter 2 to access a bank account\n\n";
std::cin >> st1;
if (st1 == 1) {
int n = 1;
for(int i = 0; i < n; i++){
bank newAccount; //we create new Account
newAccount.setOwnership(); //set the values
bankAccounts.emplace_back(newAccount); //add it to vector
std::cout << "You have succsesfully created your bank account!\n\n";
n++;
j++;
break;
}
} else if (st1 == 2) {
std::cout << "Please choose which bank account you would like to access\n\n";
for(int i = 0; i < bankAccounts.size(); i++) { //note vectors have size function to tell you the size of it. you can use this to loop through its items
std::cout << i+1 << ". ";
//bankAccounts[i].printOwnership();
}
std::cin >> a;
//bankAccounts[a-1].checkOwnership();
//bankAccounts[a-1].checkBalance();
break;
}
}
}
Extras:
I recommend using do while loop switch cases instead of empty for loop for statements for a form of menu:
#include <iostream>
#include <vector>
class bank {
int balance;
std::string ownedBy;
public:
bank()
{
}
void setOwnership() {
balance = 0;
std::cout << "Enter the name of this bank account's owner: \n";
std::cin >> ownedBy;
}
friend std::ostream& operator<<(std::ostream& os, const bank& dt);
};
std::ostream& operator<<(std::ostream& os, const bank& dt)
{
os << dt.balance;
return os;
}
int main() {
int choice;
//Array for objects from the bank class
std::vector<bank> bankAccounts;
do
{
std::cout << "What would you like to do today?\n";
std::cout << "Enter 1 to create a bank account\n";
std::cout << "Enter 2 to access a bank account\n\n";
std::cin >> choice;
switch(choice)
{
case 1:
{
bank newAccount;
newAccount.setOwnership();
bankAccounts.emplace_back(newAccount);
std::cout << "You have succsesfully created your bank account!\n\n";
break;
}
case 2:
{
std::cout << "Please choose which bank account you would like to access\n\n";
for(int i = 0; i < bankAccounts.size(); i++) {
std::cout << i+1 << ". ";
//bankAccounts[i].printOwnership();
}
int a;
std::cin >> a;
//bankAccounts[a-1].checkOwnership();
//bankAccounts[a-1].checkBalance();
break;
}
}
}while(choice != 0);
}
