Question

Look at code below:

<?php
    $output += "
    <table border='1'>
          <tr>
          <th>Session ID</th>
          <th>TeacherUsername</th>
          <th>Teacher Name</th>
          <th>Module Number</th>
          <th>Module Name</th>
          <th>Course ID</th>
          <th>Course Name</th>
          <th>Year</th>
          <th>Student Username</th>
          <th>Student Name</th>
          <th>Mark</th>
          <th>Grade</th>
          </tr>
    ";
           $total = 0;
            $count = 0;
            while ($row = mysql_fetch_array($result)) {
            $count++;
              $total += $row['Mark'];
              $output += "
          <tr>
          <td>{$row['SessionId']}</td>
          <td>{$row['TeacherUsername']}</td>
          <td>{$row['TeacherForename']} {$row['TeacherSurname']}</td>
          <td>{$row['ModuleId']}</td>
          <td>{$row['ModuleName']}</td>
          <td>{$row['CourseId']}</td>
          <td>{$row['CourseName']}</td>
          <td>{$row['Year']}</td>
          <td>{$row['StudentUsername']}</td>
          <td>{$row['StudentForename']} {$row['StudentSurname']}</td>
          <td>{$row['Mark']}</td>
          <td>{$row['Grade']}</td>
          </tr>";
            }


              $output += "        </table>";

        $average = (int)($total/$count);
        echo "<p>Average Mark: $average</p>";
    echo $output;
      ?>

For some strange reason it does not echo $output (which is at bottom of the code) properly. It is suppose to output the table but instead it echos 0, why does it output 0?

Answer 1

Don’t use javascript’s, plus but use php’s dot

$output .=

But you have to also define $output first before using .=.

so in result:

<?php
    $output = "";
    $output .= "
    <table border='1'>
          <tr>
          <th>Session ID</th>
          <th>TeacherUsername</th>
          <th>Teacher Name</th>
          <th>Module Number</th>
          <th>Module Name</th>
          <th>Course ID</th>
          <th>Course Name</th>
          <th>Year</th>
          <th>Student Username</th>
          <th>Student Name</th>
          <th>Mark</th>
          <th>Grade</th>
          </tr>
    ";
           $total = 0;
            $count = 0;
            while ($row = mysql_fetch_array($result)) {
            $count++;
              $total .= $row['Mark'];
              $output .= "
          <tr>
          <td>{$row['SessionId']}</td>
          <td>{$row['TeacherUsername']}</td>
          <td>{$row['TeacherForename']} {$row['TeacherSurname']}</td>
          <td>{$row['ModuleId']}</td>
          <td>{$row['ModuleName']}</td>
          <td>{$row['CourseId']}</td>
          <td>{$row['CourseName']}</td>
          <td>{$row['Year']}</td>
          <td>{$row['StudentUsername']}</td>
          <td>{$row['StudentForename']} {$row['StudentSurname']}</td>
          <td>{$row['Mark']}</td>
          <td>{$row['Grade']}</td>
          </tr>";
            }


              $output .= "        </table>";

        $average = (int)($total/$count);
        echo "<p>Average Mark: $average</p>";
    echo $output;
      ?>