PHP-动态填充的选择下拉列表中的pre select / save选项

Question

I have a dropdown box that holds the days 1-31 and i want to store/save what the user has previously selected if they return to the page.

My function to generate the box is:

public function fetchDDMMYYYYDropdown($select_d,$session_d) {
        $days = range (1, 31);
        $dropdown .=  '<select name="'.$select_d.'">';
        foreach($days as $key=>$name){
            if($session_d==$name){
                $session = 'selected';
            }
            $dropdown .= '<option value="'.sprintf("%02d", $name).'" selected="'.$session.'">'.sprintf("%02d", $name).'</option>';
        }
        $dropdown .=  '</select>';

        return $dropdown;
    }

And my form is on this page:

<?php
session_start();
include("includes/func.class.php");

$dob = $func->fetchDDMMYYYYDropdown('dob_d', $_SESSION['dob_d']);
?>
<form action="t35t_send.php" method="get">
<?php echo $dob;?>
<input type="submit" value="send">
</form>

And it goes to this to save the SESSION variable:

session_start();
$_SESSION['dob_d'] = $_GET['dob_d'];
$dob = $_SESSION['dob_d'];
echo $dob;

I can tell that the $_SESSION['dob_d'] is correct and saved as i can output it inside both the function and the initial form page - so it's just the following which must not be right but at the moment the dropdown box just resets back to the first value, not the saved session:

if($session_d==$name){
    $session = 'selected';
}
$dropdown .= '<option value="'.sprintf("%02d", $name).'" selected="'.$session.'">'.sprintf("%02d", $name).'</option>';

Answer 1

try this

function fetchDDMMYYYYDropdown($select_d,$session_d) {

    $days = range (1, 31);
    $dropdown .=  '<select name="'.$select_d.'">';
    foreach($days as $key=>$name){
        if($session_d==$name){

            $session = 'selected = selected';
        }
        else
        {
            $session = '';
        }
        $dropdown .= '<option value="'.sprintf("%02d", $name).'"'.$session.'">'.sprintf("%02d", $name).'</option>';
    }
    $dropdown .=  '</select>';

    return $dropdown;
}

The Problem was if even 'selected' is there in "option" even then value gets selected and in your previous code .. 'selected will be there for every date .. so it eas showing '31'. I have changed the code so that 'selected = selected ' gets echo for the saved value.

Hope it helps you

Answer 2

A rough guess your if condition is not returning true,

Try checking the value of both variables.

Just to confirm can you replace the code as below and try.

if($session_d == sprintf("%02d", $name)){
    $session = 'selected';
}
$dropdown .= '<option value="'.sprintf("%02d", $name).'" selected="'.$session.'">'.sprintf("%02d", $name).'</option>';