javascript jQuery Multi Select Option - 检查一个选项是否被选中
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jQuery Multi Select Option - Check if a option is selected or not
提问by Abrar Jahin
I have a HTML Multi select box
我有一个 HTML 多选框
<form action="form_action.php" method="Post">
<select name="cars[]" multiple id="select_id">
<option value="all" id="option_id">All</option>
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="opel">Opel</option>
<option value="audi">Audi</option>
</select>
<input type="submit">
</form>
What I am trying to do is check if option "All" is selected or not in jQuery.
我想要做的是检查是否在 jQuery 中选择了“全部”选项。
What I have tried is
我试过的是
<script>
$(document).ready(function()
{
$('#option_id')
.click(
function()
{
if ($("#select_id option[value='all']").length == 0) { //value does not exist so add
//Do something if not selected
}
else
{
//DO something if selected
}
//$("#select_id option:selected").removeAttr("selected"); //Remove
//$("#select_id option").attr('selected', 'selected'); //Add
}
);
});
</script>
But it is not working.
但它不起作用。
Can anyone help me please?
有人可以帮我吗？
Thanks in advance for helping.
提前感谢您的帮助。
回答by AB Vyas
Please do as below code
请按以下代码操作
$('#option_id').click(function(){
if ($("#select_id option[value=all]:selected").length > 0){
alert('all is selected');
}
else{
//DO something if not selected
}
//$("#select_id option:selected").removeAttr("selected"); //Remove
//$("#select_id option").attr('selected', 'selected'); //Add
});
You can check below fiddle
你可以检查下面的小提琴
回答by Milind Anantwar
You can use :selectedselector for option to determine whether it is selected or not
您可以使用:selected选择器作为选项来确定它是否被选中
if ($("#select_id option[value=all]:selected").length > 0){
//all is selected
}
回答by Lucas
From what I can see, you're trying to detect whether it has been selected when you change the option in the <select>box, right?
据我所知，您是在更改<select>框中的选项时尝试检测它是否已被选中，对吗？
Try this:
试试这个：
$("#select_id").change(function () {
if ($(this).find("option:selected").val() == "all") {
// all is selected
} else {
// all isn't selected
}
});
