如何检查select选项是否具有属性"value"？

Question

我有一个这样的select：

<select id="select-filter-item" data-hasqtip="3" oldtitle="Seleziona un tipo di servizio e filtra gli appuntamenti visualizzati sul calendario." title="" aria-describedby="qtip-3">
    <optgroup label="Servizi" type="services-group">
        <option type="provider">Tutti i trattamenti</option>
        <option value="5CFCA63F-5550-4F18-9C03-FC5B50FC67CC" type="service">Taglio capelli </option>
        <option value="B626AD6A-E59B-4D7A-875B-CE3389B11E69" type="service">Colore capelli</option>
        <option value="93003E75-A757-43F0-B2E8-C5ACDD57DBB3" type="service">Trattamenti viso</option>
        <option value="3E9924C3-6AEB-4450-B534-C06DC30F9E35" type="service">Massaggi corpo</option>
    </optgroup>
</select>

我需要确定所选选项是否具有属性value。例如，第一个选项"Tutti I trattamenti“没有任何值属性。我如何在jQuery中实现这一点？

Answer 1

一种解决方案是在所选选项上使用有属性选择器：

$("#select-filter-item").find(":selected").is("[value]")

示例Fiddle

Answer 2

这应该是可行的：

 $("#select-filter-item").change(function() {
  var txt = $("#select-filter-item").find(":selected").is("[value]")

   if (txt) {
    alert("has a value")
  } else {
   alert("does not have a value")
  }
});

小提琴https://jsfiddle.net/7sm9xh31/3/

Answer 3

希望这能帮上忙

$("#select-filter-item").on("change",function(){
    if ($('#select-filter-item option:selected').attr('value') != undefined) {
        console.log("the selected option have the attribute value.")
    }else {
        console.log("the selected option doesn't have any value.")
    }
});