We want our function to return -1 if the board is not solved yet, 1 if X won, 2 if O won, or 0 if it's a cat's game (i.e. a draw). You may assume that the board passed in is valid in the context of a game of Tic-Tac-Toe.

Tic-Tac-Toe Checker

function isSolved(board) {     

            if ((board[0][0] == 1 && board[0][0] == board[1][1] &&
               board[1][1] == board[2][2]) || (board[0][2] == 1 &&  board[0][2] == board[1][1] &&
               board[1][1] == board[2][0])) return 1;
            else if ((board[0][0] == 2 && board[0][0] == board[1][1] &&
               board[1][1] == board[2][2]) || (board[0][2] == 2 &&  board[0][2] == board[1][1] &&
               board[1][1] == board[2][0])) return 2;
            
            for (var i =0; i<3; i++) 
            {              
              if(board[i][0] == board[i][1] &&
              board[i][1] == board[i][2] && board[i][0] == 1 && board[i][1] == 1 
              && board[i][2] == 1) return 1;  
              else if (board[i][0] == board[i][1] &&
              board[i][1] == board[i][2] && board[i][0] == 2 && board[i][1] == 2 
              && board[i][2] == 2) return 2;
              }
              
               for (var i =0; i<3; i++) 
               {
              if (board[0][i] == board[1][i] &&
              board[1][i] == board[2][i] && board[0][i] == 1 && board[1][i] == 1 
              && board[2][i] == 1) return 1;
              else if (board[0][i] == board[1][i] &&
              board[1][i] == board[2][i] && board[0][i] == 2 && board[1][i] == 2 
              && board[2][i] == 2) return 2;
             // else if (board[i][i] == 0) return -1;
            }  
            
            for (var i =0; i<3; i++) 
               { 
              for (var j = 0; j < 3; j++){
               if (board[i][j] == 0)
               return -1;                          
               }
               }
            for (var i =0; i<3; i++) 
               { 
              for (var j = 0; j < 3; j++){
               if (board[i][j] != 0)
               return 0;                          
               }
               }
            
}