选择（表格）中更改选定的选项 [英] Change selected option in select (form)

问题描述

 < select name =item [type]> 
< option value =0class =dr>第一个< / option> 
< option value =1class =dr> Second< / option> 
< option value =2class =dr>第三< / option> 
< option value =3class =dr>第四< / option> 
< / select> 
  

我想检查变量 isset（$ test）被定义。如果是这样，那么我想更改值等于 $ test 的选项。像这样<选择选项>

例如。 $ test = 3 ;所以，选择的选项应该是第四个。如果 $ test 为空或未定义，那么第一个应该是选中的选项。

解决方案

< select name =item [type]id =selectBoxId>
< option value =0class =dr>第一个< / option>
< option value =1class =dr> Second< / option>
< option value =2class =dr>第三< / option>
< option value =3class =dr>第四< / option>
< / select>


< script type =text / javascript>
var test =<？= $ test;？>;
if（test！=''&& parseInt（test））{
document.getElementById（'selectBoxId'）。selectedIndex = test;
}
< / script>


I have an intial group of options like these:

<select name="item[type]">
    <option value="0" class="dr">First</option>
    <option value="1" class="dr">Second</option>
    <option value="2" class="dr">Third</option>
    <option value="3" class="dr">Fourth</option>
</select>

I want to check if a variable isset($test) is defined. If it is, then I want to change the option selected where the value is equal of $test. Something like this <OPTION SELECTED>

For example. $test = 3; so, the option selected should be fourth. If $test is empty or not defined, then the first should be the option that is selected.

解决方案

<select name="item[type]" id="selectBoxId">
<option value="0" class="dr">First</option>
<option value="1" class="dr">Second</option>
<option value="2" class="dr">Third</option>
<option value="3" class="dr">Fourth</option>
</select>


<script type="text/javascript">
    var test = "<?= $test; ?>";
    if (test != '' && parseInt(test)) {
        document.getElementById('selectBoxId').selectedIndex = test;
    }
</script>

这篇关于选择（表格）中更改选定的选项的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！