Why do I keep getting a redefinition of formal parameter error

Question

#include <iostream>
using namespace std;
void  mf_option(int player1, int player2);
void  mf_option2(int player1, int player2);
void  mf_option3(int player1, int player2);


int main()
{
    int player1, player2;
    cout << "\n\n\nWlcome to \"Rock Paper Scissor game\"\n";

    cout << " Type 0 for rock, 1 for paper , and 2 for scissors\n";
    cout << "Player 1, choose 0, 1 or 2: ";
    cin >> player1;
    system("clear");
    cout << " Type 0 for rock, 1 for paper , and 2 for scissors\n";
    cout << "Player 2, choose 0, 1 or 2: ";
    cin >> player2;
    system("clear");

    cout << "\n\nplayer 1, you chose " << player1 << " and player 2 you        chose " << player2 << "\n\n";
    mf_option(player1, player2);
    mf_option2(player1, player2);
    mf_option3(player1, player2);
    return 0;
}

void mf_option(int player1, int player2)
{
    int player1, player2;
    if (player1 == 0)
    {
        if (player2 == 0)
            cout << "It's a tie!\n\n\n\n";
        else if (player2 == 1)
            cout << "Paper Beat rock! Player2 wins!\n\n\n\n";
        else if (player2 == 2)
            cout << "Rock beat scissors! Player 1 wins!\n\n\n\n";
    }
}
void mf_option2(int player1, int player2)
{
    int player1, player2;
    if (player1 == 1)
    {
        if (player2 == 0)
            cout << "Paper beat rock! Player 1 wins!\n\n\n\n";
        else if (player2 == 1)
            cout << "It's a tie!\n\n\n\n";
        else if (player2 == 2)
            cout << "Scissors beat paper! Player 2 wins!\n\n\n\n";
    }
}
 void mf_option3(int player1, int player2)
{
    int player1, player2;
if (player1 == 2)
    {
        if (player2 == 0)
            cout << "Rock beat scissors! Player 2 wins!\n\n\n\n";
        else if (player2 == 1)
            cout << "Scissors beat paper! Player 1 wins!\n\n\n\n";
        else if (player2 == 2)
            cout << "its a tie!\n\n\n\n";
    }
}

when i try to run this program it says that i have a redefinition of formal parameter errors. the error occurs on lines 35, 48, 61. The error is for player1 and player2. can someone also please explain the point of a user defined function

Answer 1

The problem is here:

void mf_option(int player1, int player2)
{
    int player1, player2;
...

You are defining variables with the same names as those being passed in.