How to make a vector of classes in C++?

Question

I am trying to make a vector that stores cities and their time zones.

I have declared the class City and I want to output the cityName of every City in the vector.

#include <iostream>
#include <string>
#include <vector>
#include <cmath>

class City
{
    public:
        string cityName;
        char countryIso1;
        char countryIso2;
        int offset;
        City(string aCityName, char aCountryIso1, char aCountryIso2, int aOffset) {
            cityName = aCityName;
            countryIso1 = aCountryIso1;
            countryIso2 = aCountryIso2;
            offset = aOffset;
        }
};



vector<City> cities = {
    {"Abidjan", 'C', 'I', 0},
    {"Lagos", 'N', 'G', 60}
};

/* ---------- MAIN ---------- */
int main() {
    for (int i = 0; i < cities.size(); i++)
    {
        cout << cities[i].cityName << endl;
    }
    
    return 0;
}

The error I got in the terminal:

error: non-aggregate type 'vector<City>' cannot be initialized
      with an initializer list
vector<City> cities = {
             ^        ~

Answer 1

sizeof(cities) is incorrect. That's returning the size of the data your entire array occupies, not the the amount of elements in your array. Change it to sizeof(cities) / sizeof(cities[0])

More info here

Edited to add the correction:

int main() {
    for (int i = 0; i < sizeof(cities) / sizeof(cities[0]); i++)
    {
        cout << cities[i].cityName << endl;
    }
    
    return 0;
}

Answer 2

In C++, it's always better to use vector or array container over raw arrays:

This is how I would use an Array container:

std::array<City,3> arr_of_cities;

This is how I would use a Vector container:

std::vector<City> vec_of_cities;

Adding elements:

vec_of_container.push_back(<City object>);

Accessing elements:

vec_of_containers.at(<index>);  
or  
vec_of_container[<index>]; //the first one is better though 

(Same for array container)