C++ functions won't return values - c++

Question

#include<iostream>
#include<cstdlib>
#include<string>
#include<time.h>
using namespace std;
//Functions
// player strategy
int strategy(int user1Strat, int user2Strat);
// player total score per round
int currentScore();
// Display game result
void printResults();
int main()
{
int total_player1 = 0; // player 1 current score
int total_player2 = 0; // player 2 current score
int player1_strat= 0; //player 1 strategy for each turn
int player2_strat = 0; // player 2 strategy for each turn
// seed the random number generator.
srand(static_cast<int> (time(NULL)));
// get strategy for each player using functions <strategy>
strategy(player1_strat, player2_strat);
cout << player1_strat << endl << player2_strat << endl;
system("pause");
return 0;
}
int strategy(int user1Strat, int user2Strat)
{
int x,
y;
cout << "Enter player1's roll until strategy: ";
cin >> user1Strat;
cout << "Enter player2's roll until strategy: ";
cin >> user2Strat;
x = user1Strat;
y = user2Strat;
return x, y;
}
While calling for function strategy in the function main it will execute how it should, but once I ask to return the value it will just return
Enter player1's roll until strategy: 10
Enter player2's roll until strategy: 5
0
0
press any key to contiue...
Does anyone know why this is happening or what is causing it, was my error in the strategy function? Or upon calling it?

Answer 1

strategy(player1_strat, player2_strat); in your main() do nothing after receiving inputs so you won't see any change on player1_strat and player2_strat.
If you want to modify player1_strat and player2_strat in strategy, you could do that by referencing:
void strategy(int& user1Strat, int& user2Strat)
{
cout << "Enter player1's roll until strategy: ";
cin >> user1Strat;
cout << "Enter player2's roll until strategy: ";
cin >> user2Strat;
}
or you could return "multiple value" by using std::pair:
//#include <utility>
std::pair<int, int> strategy(int user1Strat, int user2Strat)
{
int x, y;
cout << "Enter player1's roll until strategy: ";
cin >> user1Strat;
cout << "Enter player2's roll until strategy: ";
cin >> user2Strat;
x = user1Strat;
y = user2Strat;
return std::make_pair(x, y);
}
//main()
std::pair<int, int> result = strategy(player1_strat, player2_strat);
x = result.first;
y = result.second;

Answer 2

You can only return a single object from a function. return x, y; does not return x and y but only y. If you want to update multiple variables, give them to the function as references and change their value inside the function.
Edit:
As mentioned by #Keith Thompson in the comments, the comma actually is an operator in this statement. It evaluates x (not much to do there), discards the result and then evaluates and returns the second argument y.