给它起一个名字[]，例如：

<select id="industryExpect" name="industryExpect[]" multiple="multiple">
    <option value="1">item1</option>
    <option value="2">item2</option>
    <option value="3">item3</option>
</select>

然后在您的$_POST数组中，您将获得所有选定选项的数组：

// assuming that item1 and item3 were selected:
print_r($_POST['industryExpect']);
/*
array
(
    0 => 1
    1 => 3
)
*/

启动 Html 文件。前任。一个.html

<form action="process.php" method="post">
    <select name="names[]" multiple="multiple">
    <option value="john">john</option>
    <option value="jack">jack</option>
    </select>
    <input type=hidden name=submitted>
    <input type=submit name=submit>
</form>

进程.php：

<?php
print_r( $_POST['names'] );
?>