Javascript 多时间数组访问不起作用

Question

>我正在尝试使客户端能够编辑JS源并以以下格式定义多维数组：

imageArray[0][0][0][0] = 'image000.jpg';
imageArray[0][0][0][1] = 'image0001.jpg';
...
imageArray[1][0][0][0] = 'image1000.jpg';
imageArray[1][0][0][1] = 'image1001.jpg';

我做了一些动态矩阵，这样JS就不会因为未初始化的数组而输出错误，现在客户端可以定义数组了。

问题是当我尝试打印一些图像时，对于某些数组（子数组）存在问题。

如果您选中检查此附加文档：https://dl.dropboxusercontent.com/u/58889914/tmp/bt4-forum.html 您将看到它打印了错误的图像alert()

你知道问题是什么吗？

提前非常感谢。

附件内容：

<script type="text/javascript">
/// CONFIG ////
function initArray(maxRows, maxCols)
{
    var imageArray = [];
    for( c= 0; c < maxRows; c++){
        imageArray.push(recurGenCol(1, maxRows, maxCols));
    }
    return imageArray;
}
function recurGenCol(col, maxRows, maxCols)
{
    if(col >= maxCols){
        return "";
    }
    var row_col = [];
    row_col = recurGenCol(col+1, maxRows, maxCols);
    var row_row = [];
    for(k = 0; k < maxRows; k++)
    {
        row_row.push(row_col);
    }
    return row_row;
}
// INIT:
var rows = 10;
var cols = 5;
var imageArray = initArray(rows, cols);
//console.log(imageArray);
// END CONFIG. Start definng array //
//var imageArray = imageArraya;

imageArray[0][0][0][0] = 'image_0_0_0_0.jpg';
imageArray[0][0][0][1] = 'image_0_0_0_1.jpg';
imageArray[0][0][0][2] = 'image_0_0_0_2.jpg';
//console.log( imageArray[0][0][0][1]);

imageArray[0][0][0][3] = 'image_0_0_0_3.jpg';
imageArray[0][0][0][4] = 'image_0_0_0_4.jpg';
imageArray[0][0][1][0] = 'image_0_0_1_0.jpg';
imageArray[0][0][1][1] = 'image_0_0_1_1.jpg';
imageArray[0][0][1][2] = 'image_0_0_1_2.jpg';
imageArray[0][0][1][3] = 'image_0_0_1_3.jpg';
imageArray[0][0][2][0] = 'image_0_0_2_0.jpg';
imageArray[0][0][2][1] = 'image_0_0_2_1.jpg';
imageArray[0][0][2][2] = 'image_0_0_2_2.jpg';
imageArray[0][0][3][3] = 'image_0_0_2_3.jpg';
imageArray[0][0][3][0] = 'image_0_0_3_0.jpg';
imageArray[0][0][3][1] = 'image_0_0_3_1.jpg';
imageArray[0][0][3][2] = 'image_0_0_3_2.jpg';
imageArray[0][0][3][3] = 'image_0_0_3_3.jpg';
imageArray[0][1][0][0] = 'image_0_1_0_0.jpg';
imageArray[0][2][0][0] = 'image_0_2_0_0.jpg';
imageArray[0][3][0][0] = 'image_0_3_0_0.jpg';
imageArray[0][3][0][1] = 'image_0_3_0_1.jpg';
imageArray[0][3][0][2] = 'image_0_3_0_2.jpg';
imageArray[0][3][0][3] = 'image_0_3_0_3.jpg';
imageArray[1][0][0][0] = 'image_1_0_0_0.jpg';
imageArray[1][0][0][1] = 'Image_1_0_0_1.jpg';
imageArray[1][0][0][2] = 'image_1_0_0_2.jpg';
imageArray[2][0][0][0] = 'image_2_0_0_0.jpg';
imageArray[2][0][0][1] = 'image_2_0_0_1.jpg';
imageArray[2][0][0][2] = 'image_2_0_0_2.jpg';
imageArray[2][0][0][3] = 'image_2_0_0_3.jpg';
imageArray[2][1][0][0] = 'image_2_1_0_0.jpg';
imageArray[2][1][0][1] = 'image_2_1_0_1.jpg';
//imageArray[6][1][0][1] = 'image_2_1_0_1.jpg';
var img =imageArray[0][0][1][0];
//console.log(log);
alert(img);


</script>

Answer 1

解决方案

这花了我一些时间...但我享受每一秒！

function initArray(maxRows, maxCols){
  var c = -1, farray = [];
  var recursive = function(array){
    c++;
    for(var r = 0; r < maxRows; r++){ 
      if(c == maxCols) array[r] = '';
      else array[r] = recursive([]);
    }
    c--;
    return array;
  };
  return recursive(farray);
}

Answer 2

我支持拉斐尔的解决方案。但我想弄清楚为什么原始代码无法按预期工作。

在许多编程语言中，内存中的多个位置可以指向同一位置。通常，这是使用命名变量完成的。所以这里有一个简单的例子...

a = b = c = {hello: "there"};
// now a.hello would mean "there",
// so would b.hello and c.hello
c.hello = "bye";
// now, even a.hello would mean "bye";

但它不必像这样做，数组索引实际上可以以相同的方式运行。

因此，请注意我如何注释您的代码并添加新的控制台日志。你看到的是，在很多情况下，你把同一个对象推到多个地方。当你这样做时，在一个地方更改它的值会在任何地方改变它，因为它们只是对同一事物的引用。

function initArray () {
    // This is the first point any array ever actually exists...
    var funArray = [];
    console.log('Just created the funArray.');
    for (i= 0; i < 10; i++){
        // Does ten pushes to the funArray with whatever
        // recurGenCol returns...
        funArray.push(recurGenCol(1, 10, 5));
        console.log('Just pushed a single multi-level array to the funArray. None of these reference the same object.');
    }
    // Returns the funArray after those ten pushes...
    return funArray;
}
function recurGenCol(col, maxRows, maxCols){
    var i;
    // Here, col starts at 1 on the first iteration,
    // it then reaches 5 on the fifth iteration,
    // passing the if check, and the function returns
    // to initArray() with an empty string.
    console.log('About to check if col ('+col+') is greater than or equal to 5.');
    if (col >= 5){
    console.log('It was true! Returning to '+arguments.callee.caller.name+' with an empty string.');
        return "";
    }
    var row_col = [];
    //console.log('Just created row_col, brand new, from scratch.');
    row_col = recurGenCol(col+1, 10, 5);
    //console.log('Now row_col is equal to the what recurGenCol returns when it is called with ' + (col + 1) + ' as the first argument.');
    var row_row = [];
    for (i = 0; i < 10; i++) {
        // Does ten pushes to row_row with whatever row_col is...
        row_row.push(row_col);
    }
    // Returns back to initArray() with whatever row_row is...
    console.log('Going to return to '+arguments.callee.caller.name+' with row_row.');
    return row_row;
}
// INIT:
var imageArray = initArray();
//console.log(imageArray);
// First level is imageArray,
// Second level is row_row,
// Third level is row_col
imageArray[0][0][0][0] = 'image_0_0_0_0.jpg';
imageArray[0][0][0][1] = 'image_0_0_0_1.jpg';
imageArray[0][0][0][2] = 'image_0_0_0_2.jpg';
//console.log( imageArray[0][0][0][1]);

imageArray[0][0][0][3] = 'image_0_0_0_3.jpg';
imageArray[0][0][0][4] = 'image_0_0_0_4.jpg';
imageArray[0][0][1][0] = 'image_0_0_1_0.jpg';
var img = imageArray[0][0][1][0];
// We expect this to log 'image_0_0_1_0.jpg'
// and it does so
console.log("first: " + img);
imageArray[0][0][1][1] = 'image_0_0_1_1.jpg';
imageArray[0][0][1][2] = 'image_0_0_1_2.jpg';
imageArray[0][0][1][3] = 'image_0_0_1_3.jpg';
imageArray[0][0][2][0] = 'image_0_0_2_0.jpg';
imageArray[0][0][2][1] = 'image_0_0_2_1.jpg';
imageArray[0][0][2][2] = 'image_0_0_2_2.jpg';
imageArray[0][0][3][3] = 'image_0_0_2_3.jpg';
imageArray[0][0][3][0] = 'image_0_0_3_0.jpg';
imageArray[0][0][3][1] = 'image_0_0_3_1.jpg';
imageArray[0][0][3][2] = 'image_0_0_3_2.jpg';
imageArray[0][0][3][3] = 'image_0_0_3_3.jpg';
imageArray[0][1][0][0] = 'image_0_1_0_0.jpg';
imageArray[0][2][0][0] = 'image_0_2_0_0.jpg';
imageArray[0][3][0][0] = 'image_0_3_0_0.jpg';
imageArray[0][3][0][1] = 'image_0_3_0_1.jpg';
imageArray[0][3][0][2] = 'image_0_3_0_2.jpg';
imageArray[0][3][0][3] = 'image_0_3_0_3.jpg';
imageArray[1][0][0][0] = 'image_1_0_0_0.jpg';
imageArray[1][0][0][1] = 'Image_1_0_0_1.jpg';
imageArray[1][0][0][2] = 'image_1_0_0_2.jpg';
imageArray[2][0][0][0] = 'image_2_0_0_0.jpg';
imageArray[2][0][0][1] = 'image_2_0_0_1.jpg';
imageArray[2][0][0][2] = 'image_2_0_0_2.jpg';
imageArray[2][0][0][3] = 'image_2_0_0_3.jpg';
imageArray[2][1][0][0] = 'image_2_1_0_0.jpg';
imageArray[2][1][0][1] = 'image_2_1_0_1.jpg';
//imageArray[6][1][0][1] = 'image_2_1_0_1.jpg';
img = imageArray[0][0][1][0];
// We expect this to log 'mage_0_0_1_0.jpg' but it DOESN'T!!!.
console.log("second: " + img);

// Rules that are true:
// - At 1st level, no items are the same object
// - At 2nd and 3rd level, all items within each parent array are the same object
// - At the last level, same-index values are the same object, except if the first level array is different
console.log('Is imageArray[0][0][0][1] the same object as imageArray[0][0][0][2]?');
console.log(imageArray[0][0][0][1] === imageArray[0][0][0][2]);
console.log('Is imageArray[0][0][0][1] the same object as imageArray[0][0][1][1]?');
console.log(imageArray[0][0][0][1] === imageArray[0][0][1][1]);
console.log('Is imageArray[0][0][0][1] the same object as imageArray[0][0][1][2]?');
console.log(imageArray[0][0][0][1] === imageArray[0][0][1][2]);
console.log('Is imageArray[0][0][0][2] the same object as imageArray[0][0][1][2]?');
console.log(imageArray[0][0][0][2] === imageArray[0][0][1][2]);
console.log('Is imageArray[0][0][0][1] the same object as imageArray[0][1][0][1]?');
console.log(imageArray[0][0][0][1] === imageArray[0][1][0][1]);
console.log('Is imageArray[0][0][0][1] the same object as imageArray[1][0][0][1]?');
console.log(imageArray[0][0][0][1] === imageArray[1][0][0][1]);
console.log('Is imageArray[0][0][1] the same object as imageArray[0][0][2]?');
console.log(imageArray[0][0][1] === imageArray[0][0][2]);
console.log('Is imageArray[0][1] the same object as imageArray[0][2]?');
console.log(imageArray[0][1] === imageArray[0][2]);