C++：从主向量 object 调用 function

Question

I am trying to call printTotals() from main() . I tried person.printTotals() but it does not work because agent only calls functions within the vector STL. I checked other answers, such as C++ Calling Vectors from Function to Main and Using vector of user defined class type objects and How to create a vector of class objects in C++? .

I also checked my STL book, but this case it is not in there.

I have two questions:

1. Is there a way to call printTotals() outside of the constructor? Can I call it from main() ? I want to keep my code clean and modular, but I am unable to access it outside of the constructor.

2. Each person has 3 neighbors consisting of Person s in a vector . I thought about declaring the neighbors vector like this, but was not sure:

    vector<Person> neighbor

For a specific person with id = 3, how can I retrieve their second neighbor's voting status? Would it be:

    person[3].neighbor[1].getPersonVotingStatus()?

This is my code:

Person.h

#include <iostream>
#include <string.h>
#include <vector>

class Person
{
   public: 
     Person();
     Person( std::vector<Person> person, maxPersons);
     std::string getPersonVotingStatus(int ID);
     void printTotals();

  private:
    std::string personName;
    float personHeight;
    int personID;
    std::string isVoter;
    vector<Person>neighbor;  // <--- 
}

Person.cpp

#include <iostream>
#include <string.h>
#include <vector>


Person::Person()
{}

Person::Person(int pID, float pHeight, std::string pName, std::string isV)
{
    personID = pID;
    personHeight = pHeight;
    personName = pName;
    isVoter = isV;
}

Person::Person( std::vector<Person> person, int maxPersons)
{
    for(int = 0; i < maxPersons; i++)
    {
       person[i].personID = i;
       person[i].personHeight = i + 100;
       person[i].personName = "testName";

       if (i / 2 = 0) { 
          person[i].isVoter = "yes";
       }
       else {
          person[i].isVoter = "no";
       }
   }
           Person(person[i].personID, person[i].personHeight, person[i].personName, person[i].isVoter);

}

std::String getPersonVotingStatus( int ID)
{
    return person[i].isVoter;
}

void printTotals( std::vector<Person> person)
{
   int totalVoter = 0;
   int totalNonvoter = 0;
   
   for (int i = 0; i< person.size(); i++)
      if (person[i].isVoter == "yes") {
        totalVoter++;
   }
   else {
     totalNonvoter++;
  }  
}

main.cpp

#include <iostream>
#include <string.h>
#include <vector>

int main()
{
  int maxPersons = 10;

  std::vector<Person> person;
  Person obj( person, maxPersons);

  person.printTotals(); // <--

  return 0;
}

Answer 1

Try defining printTotals() as a static function:

class Person
{
   public: 
     static void printTotals(std::vector<Person> person);
}

Then you can call it in main like this:

Person::printTotals(person);