Question

我在通过对象向量迭代时遇到问题。

在这个成员函数中，我试图逐步遍历数组的每个元素。但是，尽管满足条件，但if语句似乎被跳过。当我在函数开始时测试listAccounts.size（）时，它会打印0。

void Account::change_balance(string name, int balance) {

    for(auto& account : listAccounts) {
        if(account.account_name == name) {
            account.account_balance += balance;
            cout << account.account_balance;
            return;
        }
    }
    cout << "account does not exist""\n";
}

因此我必须回到矢量listAccounts这是一个问题吗？这是我推回向量的函数：

void Account::init_account(string name, char type) {

        Account account;

        if (type == 'y') {              
            account.account_type = 1;
        } else if (type == 'n') {
            account.account_type = 0;
        }

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

        listAccounts.push_back(account);
        cout << listAccounts.size() << "\n";
        }

每次用户在main中输入“create”时，都会调用相同的函数。每次用户在main中输入'transaction'时都会调用change_balance函数。

这是类定义：

class Account {
    public:
        string account_name;
        bool account_type;      
        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;

该计划应创建一个名称为＆amp;的帐户。类型，并回滚到listAccounts，以及在listAccounts中使用account_name = name更新vector元素的余额。

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

class Account {
    public:
        string account_name;
        bool account_type;      
        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;

    cout << listAccounts.size();    //test to see size before pushback

    if (type == 'y') {              
        account.account_type = 1;
    } else if (type == 'n') {
        account.account_type = 0;
    }

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

    listAccounts.push_back(account);
    cout << "\n" << listAccounts.size() << "\n";    //test to see size
    }

void Account::change_balance(string name, int balance) {

    cout << listAccounts.size() << " accounts to check\n";
    for(auto& account : listAccounts) {
        cout << "Testing " << account.account_name << "\n";
        if(account.account_name == name) {
            account.account_balance += balance;
            cout << account.account_balance;
            return;
        }
    }
    cout << "account does not exist""\n";
}


void Account::remove_account(string name) {
    auto iter = std::find_if(listAccounts.begin(), listAccounts.end(), 
             [&](const auto& s){ return s.account_name == name; });
    if(iter != listAccounts.end())
        listAccounts.erase(iter);  
}


//main
int main() {

    char action;
    string names;
    char types;
    int balance;
    Account account;

while(action != 'q') {
    int i = 0;
        cin >> action >> names;

        if (action == 'c') {
            cin >> types;
            account.init_account(names, types);
            i++;
        }

        else if (action == 't') {
            cin >> balance;
            account.change_balance(names, balance);  
        }

        else if (action == 'r'); {
            account.remove_account(names);
        }
    return 0;
    }

回退到矢量对象C ++的问题

0 个答案: