如何比较从下拉框中选择的值与数组元素？

I have a php file with 2 arrays in it

//script containing all the rublics and subrublics

$rublic[0]='rublic1';
$rublic[1]='rublic2';
$rublic[2]='rublic3';
$rublic[3]='rublic4';
$rublic[4]='rublic5';

$subrublic[0]='subrublic1';
$subrublic[1]='subrublic2';
$subrublic[2]='subrublic3';
$subrublic[3]='subrublic4';
$subrublic[4]='subrublic5';

?>

The elements of these arrays are shown in the drop-down box. What I need to do is to grab the element which the user chose from the box and write the index number of the choice selected into a database field. How could I do that?

I will post my code here even though I realize that my approach to this problem is completely wrong from the start :(

        //add the index number of the rublic and the subrublic to the db
    include('rublics.php');
    if(isset($_POST[' article_type']) && ($_POST['article_type'] != '0')){
        $rublic_selected = $_POST['article_type'];
        for($count_rublic=0;  $count_rublic<=10;  $count_rublic++){
            if($rublic_selected == $rublic[$count_rublic]) {
                $rublic_selected = $count_rublic;
            }
            if($rublic_selected == $subrublic[$count_rublic]){
                $rublic_selected = $count_rublic;
            }
        }
    } else {
        echo 'You did not make the selection. Please choose the type of the article.';
    }

Your dropdown can/should use the index numbers for the value attribute on the option elements. Ie:

<select id="article_type" name="article_type">
<option value="0">rublic1</option>
<option value="1">rublic2</option>
<option value="2">rublic3</option>
<option value="3">rublic4</option>
<option value="4">rublic5</option>
</select>

Then when the form is POSTed to your PHP script, you will already have the correct index number to write to the database.

Try this, it should be a good start:

$rublic[0]='rublic1';
$rublic[1]='rublic2';
$rublic[2]='rublic3';
$rublic[3]='rublic4';
$rublic[4]='rublic5';

$subrublic[0]='subrublic1';
$subrublic[1]='subrublic2';
$subrublic[2]='subrublic3';
$subrublic[3]='subrublic4';
$subrublic[4]='subrublic5';

//$user_input = 'rublic3';
$user_input = 'subrublic4';

$options = array('rublic', 'subrublic');
foreach($options as $option_key => $option_value)
{
    foreach($$option_value as $key => $value)
    {
        if($value == $user_input)
        {
            echo 'found it at ', $option_value, ' ', $key;
            break;
        }
    }
}

Basically, I loop through both arrays until I find the string that matches the correct user input and return the name of the array it was found in (rublic or subrublic) plus the index of that array.