如何使用jquery更改选择标记属性的名称

Question

首先，当我从select标签中选择一个值时。更改复选框的输入值。

​

window.addEventListener("load", function() { // on page load
  document.getElementById("myselectbox1").addEventListener("change", function() {
    document.getElementById("mycheckbox1").value = this.value;
  });
  document.getElementById("mycheckbox1").addEventListener("change", function() {
    console.log(this.value);
  });
});

<input type="checkbox" name="id" value="" id="mycheckbox1">

<select name="cat-1" id="myselectbox1">
  <option value="">Choose</option>
  <option value="100">Value1</option>
  <option value="200">Value2</option>
</select>

​

如何将cat-2的名称更改为cat-1的选定值

例如，如果我选择value1 (它的value=100)，我希望将cat-2的名称更改为cat-100

<input type="checkbox" name="id" value="" id="mycheckbox1">

<select name="cat-1" id="myselectbox1">
<option value="">Choose</option>      
<option value="100">Value1</option>
<option value="200">Value2</option>       
</select>

<select name="cat-2" id="myselectbox2">
<option value="">Choose</option>      
<option value="300">Value3</option>
<option value="400">Value4</option>       
</select>

Answer 1

只需从您的other question继续我的脚本

​

window.addEventListener("load", function() { // on page load
  document.getElementById("myselectbox1").addEventListener("change", function() {
    document.getElementById("mycheckbox1").value = this.value;
    const sel2 =  document.getElementById("myselectbox2");
    if (sel2 && this.value) sel2.name="c-"+this.value;
  });
  // check to see the change
  document.getElementById("mycheckbox1").addEventListener("change", function() {
    console.log(this.value);
  });
  // select to see the change
  document.getElementById("myselectbox2").addEventListener("change", function() {
    console.log(this.name,this.value)
  })  
  
  
});

<input type="checkbox" name="id" value="" id="mycheckbox1">

<select name="cat-1" id="myselectbox1">
  <option value="">Choose</option>
  <option value="100">Value1</option>
  <option value="200">Value2</option>
</select>


<select name="cat-2" id="myselectbox2">
<option value="">Choose</option>      
<option value="300">Value3</option>
<option value="400">Value4</option>       
</select>

​