无法在 select 框中的 javascript 中执行两个操作

Question

无法执行两个操作（即，我需要禁用并需要取消select select 中的 selected 选项）

我有两个 select 盒子，即 select_one 盒子是 ('1','2','3') & select_two 盒子是 ('please select' , 'test1', 'test2','test3'...等等)
并且我在 select_one 框上写了 onchange
当我从 select_box 下拉菜单中 select 编辑选项 1 或 3 时，我需要从 select_two 框中取消 select 当前值并需要显示 'please select' 选项，我还需要禁用 select_two 框。

const checkFun = ( value ) => {
                            if( value == '1' || value == '3' )
                            {
                                document.getElementById("select_two").disabled = true;
                                document.getElementById("select_two").options[0].selected = "selected";
                            } else
                            {
                                document.getElementById("select_two").disabled= false
                            }    
                        }

 Select One: <select name="testOne" id="select_one" onchange="checkFun( this.value )"><option value="1">1</option><option value="2">2</option><option value="3">3</option></select>

 Select Two: <select name="testTwo" id="select_two"><option value=""> - please select - </option><option value="test1">test1</option><option value="test2">test2</option><option value="test3">test3</option></select>

谢谢， KK

Answer 1

将 value 属性添加到 - 请 select - 选项标签如 value="0"

  <select id="select_one">
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
  </select>

 <select id="select_two">
    <option value="0"> - please select - </option>
    <option value="test1">test1</option>
    <option value="test2">test2</option>
    <option value="test3">test3</option>
 </select> 

<script>
    const boxTwo = document.getElementById('select_two');   
    document.getElementById('select_one').addEventListener('change',function(){
            boxTwo.value = 0;
            if (this.value == 2) {
                boxTwo.disabled = false;
            }else{
                boxTwo.disabled = true;
            }
    },{passive:true});
</script>

Answer 2

一切正常！

const checkFun = (value) => {
  if (value == '1' || value == '3') {
    document.getElementById("select_two").disabled = true;
    document.getElementById("select_two").options[0].selected = true;

  } else {
    document.getElementById("select_two").disabled = false
  }
}

<select name="test1" id="select_two">
  <option value=""> - please select -</option>
  <option value="test1">test1</option>
  <option value="test2">test2</option>
  <option value="test3">test3</option>
</select>

<select name="test" id="select_one" onchange="checkFun( this.value )">
  <option value="1">1</option>
  <option value="2">2</option>
  <option value="3">3</option>
</select>

Answer 3

function checkFun(value) {
  const s2 = document.getElementById("select_two");

  s2.value = "";
  s2.disabled = (value == '1' || value == '3');
}

<select name="test" id="select_one" onchange="checkFun( this.value )">
  <option value="1">1</option>
  <option value="2">2</option>
  <option value="3">3</option>
</select>

<select name="test1" id="select_two" disabled>
  <option value=""> - please select -</option>
  <option value="test1">test1</option>
  <option value="test2">test2</option>
  <option value="test3">test3</option>
</select>

无法在 select 框中的 javascript 中执行两个操作

Can't able to perform two actions in a javascript on select box

javascript

select