將二維數組傳遞給構造函數

Question

所以我有一個在測試器類中創建的二維數組，然后我試圖發送它並在構造函數中創建一個副本，但是得到一個空錯誤。 我哪里出錯了？ 構造函數：

public TheaterSeatSeller(int[][] newSeats)
{
   for(int i=0; i<newSeats.length; i++)
  {
   for(int j=0; j<newSeats[i].length; j++)
   {
    seats[i][j]=newSeats[i][j];
   }
  }

}

然后是測試員類

public static void main(String[] args){
   //initialize the available seats
   int[][] emptySeats = {
       {10,10,10,10,10,10,10,10,10,10},
       {10,10,10,10,10,10,10,10,10,10},
       {10,10,10,10,10,10,10,10,10,10},
       {10,10,20,20,20,20,20,20,10,10},
       {10,10,20,20,20,20,20,20,10,10},
       {10,10,20,20,20,20,20,20,10,10},
       {20,20,30,30,40,40,30,30,20,20},
       {20,30,30,40,50,50,40,30,30,20},
       {30,40,50,50,50,50,50,50,40,30}};
   TheaterSeatSeller mySeats = new TheaterSeatSeller(emptySeats);
   }

Answer 1

您必須在分配值之前初始化座位數組。 這應該解決它。

public TheaterSeatSeller(int[][] newSeats) {
    seats = new int[newSeats.length][newSeats[0].length];
    for (int i = 0; i < newSeats.length; i++) {
        for (int j = 0; j < newSeats[i].length; j++) {
            seats[i][j] = newSeats[i][j];
            System.out.println(seats[i][j]);
        }
    }

}