JavaScript 中的 HTML 控件数组 - 1 的复选框数组返回零长度
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HTML Control Array in JavaScript - Checkbox array of 1 returns zero length
提问by Patrick
I'm using a control array of checkboxes to capture a multiple selection
我正在使用复选框控件数组来捕获多个选择
The following code, with two checkboxes, works well and returns a value of 2as expected (or however many are there).
以下带有两个复选框的代码运行良好，并按预期返回值2（或无论有多少）。
However if there is only one checkbox item in the array, it returns a length of 0 (zero).... why is this? Shouldn't it return a length of 1?
但是，如果数组中只有一个复选框项，它返回的长度为0（零）......这是为什么？它不应该返回长度为 1 吗？
I have tried this in Internet Explorer and Chrome with the same results. As a work around I am having to include a hidden bogus checkbox in the array to make sure there is always two or more items when I run the code.
我已经在 Internet Explorer 和 Chrome 中尝试过，结果相同。作为一种解决方法，我必须在数组中包含一个隐藏的虚假复选框，以确保在运行代码时始终有两个或多个项目。
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title></title>
<script language="javascript" type="text/javascript">
function categoryOnClick() {
var selectedRows = document.searchForm.elements['categorySelect[]'];
alert(selectedRows.length);
}
</script>
</head>
<body>
<form name="searchForm" action="">
<input type="checkbox" name="categorySelect[]" id="1" onclick="categoryOnClick();"/>
<input type="checkbox" name="categorySelect[]" id="2" onclick="categoryOnClick();"/>
</form>
</body>
</html>
Code that returns 0 (zero) length...
返回 0（零）长度的代码...
<form name="searchForm" action="">
<input type="checkbox" name="categorySelect[]" id="1" onclick="categoryOnClick();"/>
</form>
回答by
function categoryOnClick() {
var rows = document.getElementsByName('categorySelect[]');
var selectedRows = [];
for (var i = 0, l = rows.length; i < l; i++) {
if (rows[i].checked) {
selectedRows.push(rows[i]);
}
}
alert(selectedRows.length);
}
回答by Rachit Doshi
In javascript you can do
在javascript中你可以做
function categoryOnClick() {
var count = document.querySelectorAll("input[type=checkbox]").length;
var checkedElements = 0;
for (var i = 0; i < count; i++) {
checkedElements = checkedElements + parseInt((document.querySelectorAll("input[type=checkbox]")[i].checked) ? 1 : 0);
}
alert(checkedElements);
}
and in jquery :
在 jquery 中：
function categoryOnClick() {
alert($('input:checked').length)
}
Hope that helps
希望有帮助
回答by derHofbauer
You can do this using jQuery:
您可以使用 jQuery 执行此操作：
function categoryOnClickjQuery() {
var selectedRows = $('form input').attr('name', 'categorySelect[]');
alert(selectedRows.length);
}
