How to swap columns in java two dimensional array?

Question

Java

Hello. I have a two dimensional array int[][] board. I need to swap any columns in it. I tried to swap the lines (code below), everything worked out, but in the case of strings, the program does not require you to write the second []. And what about columns? I don’t understand what to indicate in the first parentheses, they can’t be skipped, can they?

int[][] boardCopy = new int[board.length][board.length];
    boardCopy[0] = board[0];
    board[0] = board[2];
   board[2] = boardCopy[0];

Answer 1

Unlike rows, which you can copy all at once, you can't copy columns
one by one.