javascript jQuery 检查复选框是否被选中，然后将值添加到输入字段
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/11976476/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
jQuery Check if Checkbox is Checked, then Add Value to Input Field
提问by RevConcept
I have a shopping cart checkout page and I'm trying to add a "gift" option. What needs to happen: Once the checkbox is selected for "Send Order As Gift", a value needs to be assigned to a hidden input field so that the information is moved onto the confirmation page and various receipts.
我有一个购物车结帐页面，我正在尝试添加一个“礼物”选项。需要做什么：一旦选中“将订单作为礼物发送”的复选框，需要为隐藏的输入字段分配一个值，以便将信息移动到确认页面和各种收据上。
HTML:
HTML：
<h3>Send Order As Gift</h3>
<ul>
<li class="fc_row fc_gift"><label for="gift" class="fc_pre">This is a gift,
please do not include a receipt.</label>
<input type="checkbox" name="gift" id="gift" class="checkbox" value="" />
<input type="hidden" name="Gift" id="gift-true" value="" /></li>
<script type="text/javascript">
$(document).ready(function(){
$("#gift-true").input( $('#edit-checkbox-id').is(':checked').val() + "Yes");
});?
</script>
</li>
<li class="fc_row fc_gift_message"><label for="Gift Message">Include a message
(limit 100 characters):</label>
<textarea name="Gift Message" cols="50" rows="3" maxlength="100"></textarea>
</li>
</ul>
回答by Sebastian vom Meer
You have to update your hidden field whenever the checkbox is changed:
每当更改复选框时，您都必须更新隐藏字段：
$(function(){
$('#gift').change(function() {
$("#gift-true").val(($(this).is(':checked')) ? "yes" : "no");
});
});
回答by nbrooks
Use jQuery .val()to set the value of the input element. jquery .is()returns a boolean value, so you will have to check if it is true(using an ifstatement or a ternary operator like below), then conditionally update the value. Also, you should update this value whenever the box is selected/unselected:
使用jQuery.val()设置输入元素的值。jquery.is()返回一个布尔值，因此您必须检查它是否是true（使用if如下所示的语句或三元运算符），然后有条件地更新该值。此外，无论何时选择/取消选择框，您都应该更新此值：
$(document).ready(function(){
$('#edit-checkbox-id').change(function() {
$("#gift-true").val( this.checked ? "Yes" : "" );
}
});?
Also, if your checkbox is:
此外，如果您的复选框是：
<input type="checkbox" name="gift" id="gift" class="checkbox" value="" />
The appropriate id-selector is $('#gift'), not $('#edit-checkbox-id')
合适的 id-selector 是$('#gift'), 不是$('#edit-checkbox-id')
回答by ShankarSangoli
$('#edit-checkbox-id').is(':checked')returns a boolean value true/false based on checkbox state. So you should use it as a condition and decide what to set the the value using valjQuery method. Try this.
$('#edit-checkbox-id').is(':checked')根据复选框状态返回布尔值真/假。因此，您应该将其用作条件并决定使用valjQuery 方法设置值的内容。试试这个。
$("#gift-true").val( $('#edit-checkbox-id').is(':checked') ? "Yes": "No" );
回答by csharp
you can use CSS Pseudo-classe for example :
例如，您可以使用 CSS Pseudo-classe：
var checked=$('input[id="#gift-true"]:checked').length;
var isTrue=false;
if(checked)
isTrue=true;
else
isTrue=false;
