jQuery 检查所有项目是否具有相同的类
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Check if all items have the same class
提问by John
I built a FAQ page with the option to hide and show the content underneath each question. I have a "Expand all" functionality that let the user display all the questions onclick. When a question is expanded it gets a class of "selected".
我建立了一个常见问题页面，其中包含隐藏和显示每个问题下方内容的选项。我有一个“全部展开”功能，可以让用户在点击时显示所有问题。当一个问题被扩展时，它会得到一个“选择”类。
I am trying to change the "Expand All" status when all questions (LIs) are expanded.
当所有问题 (LI) 都展开时，我试图更改“全部展开”状态。
How can I check that all the LI have the CLASS "selected" at the same time?
如何检查所有 LI 是否同时“选择”了 CLASS？
I use the EACH method to get the LIs and their CLASS.
我使用 EACH 方法来获取 LI 及其 CLASS。
Thanks in advance
提前致谢
回答by Xion
You can probably count the list items with selectedclass against all list items:
您可能可以selected针对所有列表项计算带有class 的列表项：
if ($("#questions li.selected").length == $("#questions li").length) {
// all list items are selected
}
#questionsis the element that contains your list and of course it might be different in your code, but you should get the idea.
#questions是包含您的列表的元素，当然它可能在您的代码中有所不同，但您应该明白这一点。
回答by ipr101
$("li:not(.selected)").length
Would give you the number of <li>s that do not have the 'selected' class. If this figure was zero you could run your logic.
会给你<li>没有 'selected' 类的s的数量。如果这个数字为零，你可以运行你的逻辑。
回答by Dennis
Select all list items, filter out the items belonging to a certain class and then determine whether or not there are any left over:
选择所有列表项，过滤掉属于某个类的项，然后判断是否还有剩余：
if($("li").not(".className").length > 0 ) {
//code
}
回答by James Allardice
You could compare the number of lielements to the number of lielements with the class "selected". If those numbers are the same, then all the lielements have that class:
您可以将li元素数量li与具有“selected”类的元素数量进行比较。如果这些数字相同，则所有li元素都具有该类：
if($("li").length == $("li.selected").length) {
//All li elements have class selected
}
You can do this at any point, it does not have to go inside an eachloop.
您可以随时执行此操作，不必进入each循环。
回答by Steve Mather
Or you could try this with size()
或者你可以试试这个 size()
if( $("li.success").size() == $("li").size() ){
//return true
}
回答by Jan
When i understnad you right, you want to set the class selectedto all of your li elements when clicking on a ShowAll button?
当我理解您时，您想selected在单击 ShowAll 按钮时将类设置为所有 li 元素吗？
You don't need to iterate yourself over all lielements.
您不需要对所有li元素进行迭代。
Just select them and call addClasson them:
只需选择它们并调用addClass它们：
$('li').addClass('selected');
回答by Mika Andrianarijaona
I am not sure to understand the problem but the check if a jQuery object has a class, you use .hasClass().
我不确定是否理解这个问题，但是检查一个 jQuery 对象是否有一个类，你使用.hasClass()。
