JavaScript要在屏幕上显示所选项目

Question

我正在尝试从屏幕上的多选中选择结果echo。但是我的语法不是echo屏幕上的数据。

应该改变什么才能正确显示选定的值？

<select name="dothis" size="15" multiple="multiple" tabindex="1"> 
<option value="one">one</option> 
<option value="two">two</option> 
<option value="three">three</option> 
<option value="four">four</option> 

foreach ($_GET['dothis'] as $selectedOption) 
    echo $selectedOption."\n"; 

Answer 1

这是你将如何回应一个选择的选项：

    <select name="dothis" size="15" multiple="multiple" tabindex="1"> 
    <option <?php if (isset($_GET['dothis']) == "one") { echo "selected "; } ?>value="one">one</option> 
    <option <?php if (isset($_GET['dothis']) == "two") { 
      echo "selected "; 
     } elseif (!isset($_GET['dothis'])) { 
      echo "selected "; 
     }?>value="two">two</option> 
    <option <?php if (isset($_GET['dothis']) == "three") { echo "selected "; } ?>value="three">three</option> 
    <option <?php if (isset($_GET['dothis']) == "four") { 
      echo "selected "; 
     } elseif (!isset($_GET['dothis'])) { 
      echo "selected "; 
     }?>value="four">four</option> 
    <?php 
    foreach ($_GET['dothis'] as $selectedOption) 
     echo $selectedOption."\n";