我希望页面在下拉列表中没有选择时发布我设置的值(“空白”)。但是,我希望选择并禁用第一个选项。当存在禁用时,有没有办法解决“空”值?
<form onsubmit="check()">
<select id="test0">
<option value="" selected="selected" disabled="disabled">Select</option>
<option value="Bob">Bob</option>
</select>
<select id="test1">
<option value="" selected="selected" disabled="disabled">Select</option>
<option value="John">John</option>
</select>
<select id="test2">
<option value="" selected="selected" disabled="disabled">Select</option>
<option value="Alice">Alice</option>
</select>
<select id="test3">
<option value="" selected="selected" disabled="disabled">Select</option>
<option value="Ken">Ken</option>
</select>
</form>
function check() {
let a = '#test';
var isEmpty = true;
for (let i = 0; i < 4; i++) {
var p = $(a + i).val();
if (p != '') {
isEmpty = false;
}
}
if (isEmpty) {
$('#test0').val('BLANK');
}
};
如果无法为现有选择设置新值,那么我将添加一个隐藏输入#test3