java - How to add arrays to ArrayList? -

i have int[3][3] array , contains 0 or 1 values, if value 1 want add coordinates of value in arraylist int[2] array, don't know why add last 1-value coordinates, what's problem?

public static void main(string[] args) {      random random = new random();     int[] coordinates = new int[2];     arraylist<int[]> arraylist = new arraylist<>();     int[][] board = new int[3][3];      (int = 0; < board.length; i++) {         (int j = 0; j < board[i].length; j++) {             board[i][j] = random.nextint(2);         }     }      (int = 0; < board.length; i++) {         (int j = 0; j < board[i].length; j++) {             system.out.print(board[i][j] + " ");             if (board[i][j] == 1){                 coordinates[0] = i;                 coordinates[1] = j;                 arraylist.add(coordinates);              }         }         system.out.println();     }      system.out.println("coordinates of cells contain 1 value");      (int[] coordianate : arraylist) {         (int = 0; < coordianate.length; i++) {             system.out.print(coordianate[i] + " ");         }         system.out.println();     } } 

}

output:

1 0 1  1 1 0  1 1 0  coordinates of cells contain 1 value 2 1  2 1  2 1  2 1  2 1  2 1  

you need create new coordinates array each i,j pair want place in list. placing same array multiple times remembers last set pair.

in other words need

if (board[i][j] == 1) {     coordinates = new int[2];//add line     coordinates[0] = i;     coordinates[1] = j;     arraylist.add(coordinates);  }