如何将值从两个select传递到一个onchange函数 - How to pass value from two select to one onchange function?

How to pass value from two select to one onchange function?

我有多个动态下拉列表。前一个下拉列表的值依赖于前一个下拉列表的值。我有一个下拉菜单，其中的值取决于来自两个下拉菜单的值。下拉列表的代码。

<select name="batch" id="batch-list" onChange="getSubject(this.value);" class="form-control" required>
  <option value="">Select Batch</option>
</select>
<select name="semester" id="semester-list" class="form-control" required>
  <option value="">Select Semester</option>
</select>
//The value of the below select are dependent on the values from batch and semester 
<select name="subject" id="subject-list" class="form-control" required>
  <option value="">Select Semester</option>
</select>

单个值的onchange函数:-

function getSubject(val) {
$.ajax({
type: "POST",
url: "dropdown.php",
data:'batch_id='+val,
success: function(data){
    $("#subject-list").html(data);
}
});

}

上面的onchange函数只从批处理中获取值，我如何通过ajax在函数中传递学期的值

试试这个:

function getSubject(param1, param2) {
       $.ajax({
            type: "POST",
            url: "dropdown.php",
            data: {
                val1 : param1,
                val2 : param2
            },
            success: function(data){
            $("#subject-list").html(data);
        }
}

并命名为:

$(document).on('change', '#dropdown1_id', function(){
    var dd1 = $(this).val();
    var dd2 = $('#dropdown2').val();
    getSubject(dd1, dd2);
});