Jquery将项目添加到下拉列表中且不重复

Question

我想将元素添加到我的下拉列表中，但不重复

for (var i = 0; i < queues.entities.length; i++) {
      var queuesName = queues.entities[i].name;

 $("#brandFilter").append(
        $(new Option(queues.entities[i].name.substring(0, 2)))
      );
     
    }

这是我的列表，

 <div>
                  <b>Brand</b>
                  <select
                    class="form-control input-sm form-control-sm border-0 brandFilter"
                    id="brandFilter"
                    multiple
                    size="3"
                  >
                    <option value="-" selected>--- All ---</option>
               </select>
                 <hr />
                </div>

非常感谢

Answer 1

一个简单的解决方案是首先删除重复的实体。

  const uniqueQueuesEntities = [...new Set(queues.entities)];

  for (var i = 0; i < uniqueQueuesEntities.length; i++) {
    var queuesName = uniqueQueuesEntities[i].name;

    $("#brandFilter").append(
      $(new Option(uniqueQueuesEntities[i].name.substring(0, 2)))
    );
  }