棘手的Javascript循环 [英] Tricky Javascript Looping

问题描述

我有一个我想要显示的广播电台的XML列表，但我认为它涉及一些我无法弄清楚的嵌套FOR循环。


这是我的XML示例：

I''ve got an XML list of radio stations that I want to display, but I think it involves some nested FOR loops that I can''t quite figure out.

Here''s a sample of my XML:

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推荐答案

您遇到的一个问题是< I>的childNodes 的。请注意，子节点不仅是一个元素，甚至元素之间的空格也算作子节点！你最好用 getElementsByTagName（）。


现在主要问题是， x 和 y 代表独立的 NodeLists（非常简单的数组），所以请注意你需要索引的地方（以及哪个变量去那里）。


如果你回报看不出我的意思。


PS：使用FireBug会对你有很大帮助


旁注：建议用使用DOM方法（或 .innerHTML ）显示结果，而不是通过 document.write（）

one problem you have is using childNodes. mind that a child node is not only an element, even whitespace between elements counts as child node! you?re better off with getElementsByTagName().

now to the main problem, x and y represent independent NodeLists (very simple arrays), so take care where you need an index (and which variable goes there).

report back if you can?t see what I mean.

PS: using FireBug will help you a great deal here

side note: it is recommended to display the results using DOM methods (or .innerHTML) rather than through document.write()

感谢您的回复。


我可以看到如何使用getElementsByTagName（）直接访问< station>节点而不是使用childNodes，但我不知道我将如何显示每个州的那些节点。那仍然会使用某种嵌套的FOR循环，或者可能是IF语句吗？我想这就是我滥用x和y变量导致我误入歧途的地方。


我确实切换到使用innerHTML，至少只列出状态：

Hi, thanks for the response.

I can see how using getElementsByTagName() would directly access the <station> nodes instead of using childNodes, but I don''t see how I would display just the ones that go with each state. Would that still use some sort of nested FOR loops, or maybe IF statements? I guess that''s where my misuse of the x and y variables is leading me astray.

I did switch to using innerHTML, at least to just list the states:

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@npm


访问< state> s就像访问<站GT; S。从一般的角度来看，它们是相同的。

@nn


您的原始代码在修复 childNodes后正常工作， x 和 y 错误。是的，你需要嵌套循环（因为你有嵌套数据（因为有办法解决这个问题，但我不认为那更好吗？））

@npm

尝试脚本选项卡，在那里你可以设置断点（通过点击行号之前和Firebug将在下一次运行中停止，这样你就可以检查每个变量（例如见为什么跳过循环）

@npm
access the <state>s like you access the <station>s. from a general point of view, they are the same.

@npm
your original code worked all right after fixing the childNodes, x and y bugs. and yes, you need nested loops (because you have nested data (of cause there are ways to work around that, but I don?t consider that better? yet))

@npm
try out the script tab, there you can set breakpoints (by clicking just before a line number and Firebug will stop there in the next run so you can inspect each of the variables (and for instance see why a loop is skipped)

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