php multiple select javascript option的操作方法

How to get multiple select value both in javascript and php?

在csdn上找到一篇这样的文章 http://blog.csdn.net/hjzdhr/archive/2009/12/22/5056546.aspx

For PHP, we must use test[] for the select name, but it doesn’t work in javascript. document.form1.test is null.

So we should use document.getElementById(‘test[]‘) or document.form1['test[]‘]. On this way, we are able to get multiple select value in both PHP and JavaScript.

1. <form name="form1">
   2. <select name="test[]" multiple="multiple" onchange="alert(document.getElementById('test[]').value);">
   3. <option value="one">one</option>
   4. <option value="two">two</option>
   5. <option value="three">three</option>
   6. <option value="four">four</option>
   7. <option value="five">five</option>
   8. </select>
   9. </form>  

于是 扩展一下javascript如何操作option呢?比如增加或者减少项

1. <select name="txtOptions[]" id="txtOptions" size="10" multiple="multiple">
   2. <option value="Foreign Exchange">Foreign Exchange</option>
   3. <option value="Share CFDs">Share CFDs</option>
   4. <option value="Metal & Commodities">Metal & Commodities</option>
   5. <option value="Indices">Indices</option>
   6. <option value="Binary Options">Binary Options</option>
   7. <option value="Option">Option</option>
   8. </select>
   9. <input name="txtNewOption" size="20" style="font-size: 100%;" type="\"text\"">
  10. <a href="javascript:doAddOption();">Add option</a>
  11. <a href="javascript:removeSelected();"><small>Remove option</small></a>
  12. <script language="javascript">
   
  14. var arOptions;
  15. arOptions = new Array(255);
  16.
  17. function doAddOption() {
  18. var newOption, strText;
  19. var txtOptions = document.getElementById('txtOptions');
  20. var txtNewOption = document.getElementById('txtNewOption');
  21. strText = txtNewOption.value;
  22. newnewOption = new Option(strText, strText);
  23. var intPosition = txtOptions.length;
  24. txtOptions.options[intPosition] = newOption;
  25. txtNewOption.value="";
  26. }
  27. function removeSelected() {
  28. var txtOptions = document.getElementById('txtOptions');
  29. txtOptions[txtOptions.selectedIndex]= null;
  30. }
  31. </script>