// just example for explanation :)
// vector containt strings
vector USERS;
// take string from 'USERS'
// under name 'user' in each time :)
for(string user : USERS){
std::cout << user << std::endl;
}
range based for loop c++
array values = {1, 2, 3, 4, 10};
// the type declaration below must be consistent with the array type
for (int x : values){ //we use a colon instead of in
cout << x << endl;
}