Leap year and non leap year into separate tables

This code will display the the leap year and non leap year from 1991 to 2100, I tried to make table one for leap year and other for non leap year but I failed.

How can I bring it in table format or in a grid system? This is for academic study.

 <!DOCTYPE html>
    <html>
    <head>
        <title>Leap Year</title>
        <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
        <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
    </head>
    <body>
        <?php  
        function isLeap($year) {
        return ((($year % 4) == 0) && ((($year % 100) != 0)));
        }

            for($year=1991; $year<=2100; $year++)  
            {  
                If (isLeap($year))  
                {   
                    $leap="$year : LEAP YEAR <br/>";
                    //echo "<div class='col-sm-12'>" . $leap . "</div>";
                    echo $leap;
                }  
                else  
                {  
                    $nonLeap="$year : Not leap year <br/>";  
                    //echo "<div class='col-sm-6'>" . $nonLeap ."</div>";       
                    echo $nonLeap;           
                }  
            }
        ?>
    </body>
    </html>

Solution

Your isLeap function is wrong. You also can refer to this post.

function isLeap($year) {
    return ((($year % 4) == 0) && ((($year % 100) != 0) || (($year % 400) == 0)));
}

for($year=1991; $year<=2100; $year++)  
{  
    if (isLeap($year))  
    {   
        $leaps[] = $year;
    }  
    else  
    {  
        $nonLeaps[] = $year;
    }
}

echo '<table><tr>';
foreach($leaps as $y)
{
  echo '<td>' . $y . '</td>';
}
echo '</tr></table>';