duanchun1852 2014-12-31 01:54
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如何同时应用add()和remove()方法?

I require 2 dropdown list name it Parent n child. I have made by child a hidden field to only appear as parent value is clicked.

Im trying to apply both add and remove method concurrently. Here is an example from w3schools on the respective add() and remove() method.

How do i integrate them both in one?

//Add() method

<!DOCTYPE html>
<html>
<body>

<form>
  <select id="mySelect" size="8">
    <option>Apple</option>
    <option>Pear</option>
    <option>Banana</option>
    <option>Orange</option>
  </select>
</form>
<br>

<p>Click the button to add a "Kiwi" option at the end of the dropdown list.</p>

<button type="button" onclick="myFunction()">Insert option</button>

<script>
function myFunction() {
    var x = document.getElementById("mySelect");
    var option = document.createElement("option");
    option.text = "Kiwi";
    x.add(option);
}
</script>

</body>
</html>

//remove() method
<!DOCTYPE html>
<html>
<body>

<form>
Select a fruit:
<br>
<select id="mySelect" size="4">
  <option>Apple</option>
  <option>Pear</option>
  <option>Banana</option>
  <option>Orange</option>
</select>
</form>
<br>

<button onclick="myFunction()">Remove selected fruit</button>

<script>
function myFunction() {
    var x = document.getElementById("mySelect");
    x.remove(x.selectedIndex);
}
</script>

</body>
</html>

Here is the websites to test the codes:

http://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_select_add

http://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_select_remove

  • 写回答

1条回答 默认 最新

  • douan0729 2015-01-30 03:46
    关注
    <!DOCTYPE html>
    <html>
    <body>
    
    <form>
      <select id="mySelect" size="8">
        <option>Apple</option>
        <option>Pear</option>
        <option>Banana</option>
        <option>Orange</option>
      </select>
    </form>
    <br>
    
    <p>Click the button to add a "Kiwi" option at the end of the dropdown list.</p>
    
    <button type="button" onclick="add()">Insert option</button>
    <button onclick="rem()">Remove selected fruit</button>
    
    <script>
    function add() {
        var x = document.getElementById("mySelect");
        var option = document.createElement("option");
        option.text = "Kiwi";
        x.add(option);
    }
    
    function rem() {
        var x = document.getElementById("mySelect");
        x.remove(x.selectedIndex);
    }
    </script>
    
    </body>
    </html>
    
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

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