JavaScript要在屏幕上顯示所選項目

Question

我正在嘗試從屏幕上的多選中選擇結果echo。但是我的語法不是echo屏幕上的數據。

應該改變什麼才能正確顯示選定的值？

<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

這是你將如何迴應一個選擇的選項：

    <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";