JavaScript 按索引对数组进行垂直排序

Question

我有这个数组:["A","B","C","D","E","F","G","H","I","J","K"、"L"、"M"、"N"、"O"、"P"、"Q"、"R"、"S"、"T"、"U"、"V"、"W","X","Y","Z"]

我从服务器获取要显示的列数，在本例中我选择了 3。

到目前为止，我的这个函数工作正常，除非我的索引等于数组长度，否则顺序会出现问题，而且我不知道如何修复它。

var i;
var j;
var columns = window.columns; //3 for the example.
var lettersArray= ["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"];
var rows = Math.ceil(lettersArray.length/columns);

到目前为止我有这个:

 for (i = 0; i < rows; i++)
            {
                     for (j=0; j < lettersArray.length; j=j+rows)  
                     {

                        var index = i+j;
                        if (index>=lettersArray.length)
                        {
                            break;
                        }
                        else
                        {
                          PrintArray(lettersArray, index); 
                        }   
                     }
            }

PrintArray 函数在排序后接收索引和数组，它最终看起来像这样:

A J S 
B K T 
C L U 
D M V
E N W
F O X
G P Y 
H Q Z 
I R

但是在某个地方出了问题，看起来像:

A J S 
B K T 
C L U 
D M V
I N W
F O X
G P Y 
H Q R 
E Z

Answer 1

您的意思是您希望通过row + col * rows 迭代每个项目。您也不能在未定义上停止，因为您可能还有更多行需要处理。

以下是您可以如何执行此操作的示例，

function foo(data, cols) {
    var rows = Math.ceil(data.length / cols);
    var col, row;
    for (row = 0; row < rows; ++row)
        for (col = 0; col < cols; ++col)
            console.log(data[row + col * rows] || '');
}

其中 console.log 正在记录下一个项目或 || 空字符串。