jQuery:如何获取选中的单选按钮的索引

Question

我最近发现了一个 StackOverflow 答案，它对 how to get the value of a checked radio button using jQuery 提供了很好的说明。 :

var radioVal = $("#myFormID input:radio[name='radioFieldName']:checked").val();
alert('Selected radio button value = ' + radioVal);

现在我试图找到选中的单选按钮的从零开始的索引。我认为这会相对简单:

var radioIdx = $("#myFormID input:radio[name='radioFieldName']:checked").index();

但是，radioIdx 始终返回值 -1。关于我可能做错了什么有什么想法吗？

Answer 1

这应该有效。您可以在一行中完成所有操作，但我将其分解以使其更易于阅读:

var radioButtons = $("#myFormID input:radio[name='radioFieldName']");
var selectedIndex = radioButtons.index(radioButtons.find(':checked'));

编辑:验证您的选择器是否正确。一步步分解:

var radioButtons = $("#myFormID input:radio[name='radioFieldName']");

// this should contain the count of all your radio buttons
var totalFound = radioButtons.length;

// this should contain the checked one
var checkedRadioButton = radioButtons.find(':checked');

// this should get the index of the found radio button based on the list of all
var selectedIndex = radioButtons.index(checkedRadioButton);

哪一步没有产生预期的值(value)？

编辑:显示最终解决方案

var radioButtons = $("#myFormID input:radio[name='radioFieldName']");
var selectedIndex = radioButtons.index(radioButtons.filter(':checked'));