jQuery 计算使用jquery检查的html复选框的数量
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calculate the number of html checkbox checked using jquery
提问by bogha
how can i calculate the number of checkboxes that a user has checked using jquery?
我如何计算用户使用 jquery 选中的复选框的数量？
what i want to do is limiting the number of checking for checkboxes in a form to 10 for example and when a user exceeds this range display a warning message.
我想要做的是将表单中复选框的检查次数限制为 10，例如，当用户超出此范围时显示警告消息。
回答by Sarfraz
There are multiple methods to do that:
有多种方法可以做到这一点：
Method 1:
方法一：
alert($('.checkbox_class_here:checked').size());
Method 2:
方法二：
alert($('input[name=checkbox_name]').attr('checked'));
Method: 3
方法：3
alert($(":checkbox:checked").length);
回答by James Wiseman
This should work:
这应该有效：
alert($("input:checkbox:checked").length);
回答by Richik SC
If none of the methods above work, you probably haven't imported jQuery yet.
To import jQuery, paste this code into the <head>of your HTML.
如果上述方法均无效，则您可能还没有导入 jQuery。要导入 jQuery，请将此代码粘贴到<head>您的 HTML 中。
<script src="//code.jquery.com/jquery-1.10.2.js"></script>
I actually had the same problem while creating a product ordering page, and I wanted it to count The number of products in the cart at the order confirmation page. I referred to this post and tried all of the methods. Then I found out I did not import jQuery, so the $(':checkbox:checked')did not work.
我在创建产品订购页面时实际上遇到了同样的问题，我希望它在订单确认页面计算购物车中的产品数量。我参考了这篇文章并尝试了所有方法。然后我发现我没有导入 jQuery，所以$(':checkbox:checked')没有用。
回答by rioted
you ought to use
你应该用
alert($("input:checkbox:checked").length);
or
或者
alert($(".checkbox-class:checked").length);
if you have more forms on one page
如果一页上有更多表格
.size() (method number 1 in current accepted answer) is deprecated since jQuery 1.8
.size()（当前接受的答案中的方法编号 1）自 jQuery 1.8 起已弃用
