javascript函數參數

Question

我想將一個數組傳遞給一個函數並對其進行處理，但是我擔心，發生錯誤會說board_pt是未定義的。問題是什麼？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; 
} 

板是已經定義

Answer 1

問題一個全局數組是board_pt僅具有1個項目，並且在這些情況下的js知道board_pt作爲對象：

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是一個真正的數組，那麼它不太可能具有名爲number的屬性。你的意思是length？

Answer 3

從您的意見，你必須定義previous_boardPoint作爲一個數組。要在JavaScript中聲明數組，您需要在代碼中有 - var previous_boardPoint = [];。也有定義的每個元素（如果您有任何），如previous_boardPoint[0] = val1; previous_boarPoint[1] = val2;等

如果這些東西是不是在你的代碼，然後在所有可能的機會，你會得到board_pt爲未定義在函數set_boardPoint。