偶数/奇数确定CSS类

Question

I've read a lot of information about the determination of a even/odd number and using it to change the class of a div.

In my case I want to switch the position of divs called MessagePicture and MessageText every new message posted.

1. Picture left, Text right
2. Picture right, Text left
3. Picture left, Text right
4. ect.

This is the code I am using to display the messages, I also included one of my tries to get the even/odd code to work.

Can anyone tell me what I should change to get it to work?

    <?PHP

    $Query =
    "
            SELECT
                ID,
                NameBox,
            MessageBox,
            Code
        FROM
            messages
            ORDER BY
                ID
            DESC LIMIT 10
    ";

    $Result = mysql_query($Query);

        if(!$Result)
            {
            echo 'ERROR: '.mysql_error();
            }

        else
            {
            if(mysql_num_rows($Result) == 0)
                {
                    echo 'No results';
                }

                else
                    {
                    $i = 0;
                $class = (++$i % 2) ? 'even' : 'odd';
                    while
                    ($Row = mysql_fetch_assoc($Result))

                        echo '

<div id="MessageWrapper">
    <div id="MessagePicture" class="'.$class.'">                                                                                
        <style>                                             
        #MessagePicture { 
        background-image: url(../../../Images/'.stripslashes($Row['Code']).'.png);  
        background-repeat: no-repeat; 
        background-position: center
        </style>
        </div>

    <div id="MessageText" class="'.$class.'">

        <div id="MessageTitle">

            <h1>'.$Row['NameBox'].'</h1>

        </div>

        <div id="MessageContent">                                                   
            <p>'.nl2br($Row['MessageBox']).'</p>
        </div>

    </div>

</div>  

';}}}?>

Answer 1

Your $i always stays 0. Add $i++ in the while loop to increment it.

You can do that in one line:

$class = ($i++ % 2 == 0) ? 'even' : 'odd';

Full Example:

$i = 0;
while ($Row = mysql_fetch_assoc($Result)) {
  $class = ($i++ % 2 == 0) ? 'even' : 'odd';
  //echo ...
}