How to iterate through a vector of objects?

[runrabbitrun]

I am attempting to make a program that stores records of user accounts, including their name, balance, account type etc. Such that the user can enter a line of text denoting the desired action (create an account, withdraw etc), the account name, and account type/amount.

example of input: c josh y

c creates an account

josh is the name

y is a credit account

I am having trouble finding a way of iterating through the listAccounts vector in change_balance() such that the user can find a particular account by its name in vector listAccounts, and change the balance of that particular object in the vector.

#include <iostream>
using namespace std;
#include <sstream>
#include <vector>

class Account {
    public:
        string account_name;
        bool account_type;      //'y' = creidt account = 1, 'n' = basic account = 0
        int account_balance;
        static vector<Account> listAccounts;
        
        //member function declaration
        void init_account(string name, char type);
        void change_balance(string name, int balance);
        void remove_account(string name);
        
};

vector<Account> Account::listAccounts;


//member functions definitions
void Account::init_account(string name, char type) {
    
    Account account;
    
    if (type == 'y') {              //setting the account type  (credit/basic)
        account.account_type = 1;
    } else if (type == 'n') {
        account.account_type = 0;
    }

    account.account_name = name;
    account.account_balance = 0;

    listAccounts.push_back(account);
}

void Account::change_balance(string name, int balance) {
    
    Account account;
    //find particular account by name in vector listAccounts, and change balance
}

void Account::remove_account(string name) {
    
    //find particular account by name in vector listAccounts, and remove element
}


//main
int main() {
    
    char action;
    string names;
    char types;
    int balance;
    Account account;
    
    cin >> action >> names;
    
    if (action == 'c') {
        cin >> types;
        account.init_account(names, types);
        
    }
    
    else if (action == 't') {
        cin >> balance;
        account.change_balance(names, balance);  
    }
    
    else (action == 'r'); {
        account.remove_account(names);
    }
    
    return 0;   
}

Similarly, being able to find a vector element of listAccounts by name and removing that element.

Thanks.

[Repeater]

Create iterator to the vector of interest:

auto iter = listAccounts.begin();

Go through every element in the vector looking for the relevant one:

for ( ; iter !=  listAccounts.end(); iter++)
{
  if ((*iter).account_name == the_name_of_interest)
  {
      // do something; change it or erase
  }
}

You can erase using the iterator; http://www.cplusplus.com/reference/vector/vector/erase/

[keskiverto]

std::find_if http://www.cplusplus.com/reference/algorithm/find_if/

void foo( string name )
{
  auto it = std::find_if( accounts.begin(), accounts.end(),
                          [&name](const Account& A){ return A.account_name == name; } );
  if ( accounts.end() != it )
  {
    // use it
  }
}

[runrabbitrun]

Thanks, very helpful, I rewrote the member functions to iterate through the vector:

void Account::init_account(string name, char type) {
    
    Account account;
    
    if (type == 'y') {              //setting the account type  (credit/basic)
        account.account_type = 1;
    } else if (type == 'n') {
        account.account_type = 0;
    }

    account.account_name = name;
    account.account_balance = 0;

    listAccounts.push_back(account);

}

void Account::change_balance(string name, int balance) {
    
    auto iter = listAccounts.begin();
    
    for ( ; iter !=  listAccounts.end(); iter++) {
        if ((*iter).account_name == name) {
            (*iter).account_balance = balance;
            cout << (*iter).account_balance;
        }
        if (((*iter).account_type == 0) && ((*iter).account_balance < 0)) {
                cout << "account cannot hold negative balance""\n";
                (*iter).account_balance = (((*iter).account_balance) - (balance));
                cout << (*iter).account_balance;
        } 
    }
}

void Account::remove_account(string name) {
    
    auto iter = listAccounts.begin();
    
    for ( ; iter !=  listAccounts.end(); iter++) {
        if ((*iter).account_name == name) {
            listAccounts.erase(iter);
            break;
        }
    }
    
}

I also want to be able to iterate through the entire array in change_balance() to check if an element with name exists in the first place, but I can't think for the life of me how to search through the array to check if the name exists, if it doesn't, cout "does not exist".