javascript函數參數

Question

我想將數組傳遞給函數並對其進行處理，但是恐怕會發生錯誤，指出board_pt未定義。 問題是什么？ 這是代碼：

function set_boardPoint( board_pt,turn)
{   
    var no = board_pt.number-1;
    board[no].row = board_pt.row;
    board[no].col = board_pt.col;
    board[no].x = board_pt.x;
    board[no].y = board_pt.y;
    board[no].value = turn;
    board[no].number = board_pt.number;
}

board是已經定義的全局數組

Answer 1

問題是board_pt只有1個項目，在這種情況下，js知道board_pt是對象：

function set_boardPoint( board_pt,turn)
{   
    var no = board_pt.number-1;
  if( board[no] != undefined ) 
  {
    board[no].row = board_pt.row;
    board[no].col = board_pt.col;
    board[no].x = board_pt.x;
    board[no].y = board_pt.y;
    board[no].value = turn;
    board[no].number = board_pt.number;
}else
{
 board.row = board_pt.row;
    board.col = board_pt.col;
    board.x = board_pt.x;
    board.y = board_pt.y;
    board.value = turn;
    board.number = board_pt.number;
}
}

Answer 2

如果board_pt是一個實數組，則它不太可能具有名為number的屬性。 你是說length嗎？

Answer 3

根據您的評論，您必須將previous_boardPoint定義為一個數組。 要在JavaScript中聲明數組，您需要var previous_boardPoint = []; 在您的代碼中。 還定義了每個元素（如果有的話），例如previous_boardPoint[0] = val1; previous_boarPoint[1] = val2; previous_boardPoint[0] = val1; previous_boarPoint[1] = val2; 等等

如果這些東西是不是在你的代碼，然后在所有可能的機會，你會得到board_pt在你的函數set_boardPoint不確定。