jQuery 使用jquery获取子元素的ID并存储在变量中？
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get an id of child element and store in a variable using jquery?
提问by pixie54
I'm basically trying to do exactly what the subject suggests, but I'm getting "undefined" in my alert, and I'm not entirely sure why. I am fairly new to jquery, so, I probably have the syntax wrong, but not sure where to go from here. I'll post both of my attempts, which both yield "undefined" in the alert...
我基本上试图完全按照主题的建议去做，但是我在警报中变得“未定义”，我不完全确定为什么。我对 jquery 相当陌生，所以，我可能有语法错误，但不确定从哪里开始。我将发布我的两次尝试，它们都在警报中产生“未定义”......
//In my first attempt, I'm trying to get the id of the inner a tag
<ul>
<li id="l1" class="active"><a href="#c1">Samp 1</a></li>
<li id="l2" class=""><a href="#c2">Samp 2</a></li>
<li id="l3" class=""><a href="#c3">Samp 3</a></li>
</ul>
var selected = $(".active).children("a").attr("id");
alert(selected);
//In my second attempt, I'm trying to get the id of the currently selected li
var selected = $(".active").attr("id");
alert(selected);
回答by Vincent Robert
$(".active").children("a").attr("id");
Your <a>elements do not have an id, only an href. And using a selector instead of the children function may make your code easier to read.
您的<a>元素没有id，只有href。使用选择器代替子函数可能会使您的代码更易于阅读。
Do you mean $(".active > a").attr("href")?
你的意思是$(".active > a").attr("href")？
$(".active").attr("id");
jQuery will return the idattribute of the first element in the jQuery collection. Do you have another element with class active?
jQuery 将返回idjQuery 集合中第一个元素的属性。你有另一个带有 class 的元素active吗？
I suggest you try $("ul > li.active").attr("id")
我建议你试试 $("ul > li.active").attr("id")
回答by Nick Craver
In the first attempt, you're getting the <a>within the <li>...which doesn't have an ID, you just need this:
在第一次尝试，你得到的<a>内<li>...不有一个ID，你只需要这样的：
var selected = $(".active").attr("id");
alert(selected);
So your second attempt is correct, you can see it in action here.
所以你的第二次尝试是正确的，你可以在这里看到它的实际效果。
If you actually meant to get the idfrom the <a>element, then you need to give them IDs and your first attempt will work, you can see it here.
如果您确实打算id从<a>元素中获取，那么您需要为它们提供 ID，并且您的第一次尝试会成功，您可以在此处查看。
回答by mamoo
You're getting the wrong attribute (or you have a wrong markup). There's no "id" attribute in your a tags. You have "href" attributes, so if you're trying to geth the value of "href" you should use this:
你得到了错误的属性（或者你有一个错误的标记）。您的 a 标签中没有“id”属性。你有“href”属性，所以如果你想获取“href”的值，你应该使用这个：
var selected = $(".active).children("a").attr("href");
alert(selected);
Otherwise if you need to get the parent's id you should use:
否则，如果您需要获取父母的 id，则应使用：
var selected = $(".active).attr("id");
alert(selected);
回答by karim79
The issue with the anchors seems to be that none of the anchors you're selecting actually have an ID. Do you mean .attr("href")by any chance?
锚点的问题似乎是您选择的锚点实际上都没有 ID。你的意思是.attr("href")有任何机会吗？
