jQuery 在没有第一项的情况下对下拉列表中的项进行排序
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sort items in a dropdown list without the first item
提问by leora
I have the following code to sort the items in a dropdown list:
我有以下代码对下拉列表中的项目进行排序：
function sortDropDownListByText(selectId) {
$(selectId).html($(selectId + " option").sort(function(a, b) {
return a.text == b.text ? 0 : a.text < b.text ? -1 : 1
}))
}
this works fine except in cases where, in my first item, i have a **"Please select and item from the list" message . . **
这很好用，除非在我的第一个项目中，我有一个 **“请从列表中选择和项目”消息。. **
is there anyway i can sort the items in the select list and keep the "Please select entry" as the first item in the list always?
无论如何我可以对选择列表中的项目进行排序并始终将“请选择条目”作为列表中的第一项？
EDIT:
编辑：
In response to some of the answers, the "Please select item always has a value of 0"
针对一些答案，“请选择项目的值始终为 0”
回答by simplyharsh
function sortDropDownListByText(selectId) {
var foption = $('#'+ selectId + ' option:first');
var soptions = $('#'+ selectId + ' option:not(:first)').sort(function(a, b) {
return a.text == b.text ? 0 : a.text < b.text ? -1 : 1
});
$('#' + selectId).html(soptions).prepend(foption);
};
is your function.
是你的功能。
回答by Daniel
Theoretically, I would approach the problem by removing the "Please select" entry, sorting the list, then append it again, once the sorting is done
从理论上讲，我会通过删除“请选择”条目，对列表进行排序，然后在排序完成后再次追加来解决该问题
回答by dxh
How about always returning -1for that item?
总是回来-1买那件东西怎么样？
$(selectId).html($(selectId + " option").sort(function(a, b) {
return a.text == "Please select an item from the list" ? -1 : a.text < b.text ? -1 : 1;
});
more dynamically:
更动态：
$(selectId).html($(selectId + " option").sort(function(a, b) {
return a.text == $(selectId + 'option:first').text ? -1 : a.text < b.text ? -1 : 1;
});
回答by Tom Bartel
If the "Please select..." option has a certain value (here called "dummyVal") associated with it, you could use this in your comparison function:
如果“请选择...”选项具有与之关联的特定值（此处称为“dummyVal”），您可以在比较函数中使用它：
function sortDropDownListByText(selectId, dummyVal) {
$(selectId).html($(selectId + " option").sort(function(a, b) {
if (a.value == dummyVal) {
return -1;
}
return a.text == b.text ? 0 : a.text < b.text ? -1 : 1
}))
}
回答by rahul
Remove the first item from the select box and then append it at the first position after the sort function.
从选择框中删除第一项，然后将其附加到排序功能后的第一个位置。
$(selectId).html($(selectId + " option:not(':first-child')").sort(function(a, b) {
return a.text == b.text ? 0 : a.text < b.text ? -1 : 1
}))
回答by Ibrahim Sana
First you have to preserve the selected value, and once you finished the sorting you re-select the preserved value.
首先，您必须保留选定的值，完成排序后，您重新选择保留的值。
#store the selected value.
var selectedVal = $(selectId).val();
# start sorting.
$(selectId).html( $(selectId+" option").sort(function(a, b) {
return a.text == b.text ? 0 : a.text < b.text ? -1 : 1
}));
#re-select the preserved value.
$(selectId).val(selectedVal);
