I'm not getting values from session variable set for results - php

Question

I have created the following pages.
1. questions.php
2. functions.php
3. result.php
i have set the values of session variables on page function.php when the question form on questions.php form is submitted the functions.php code runs and the i have echo the values of session variables on result.php page. but i'm unable to get the session values result.the sessions values are resulting empty .anyone help please.
functions.php
if(isset($_POST['question_form']))
{
global $conn;
if (!isset($_SESSION['result'])) {
$result = 0;
$_SESSION['result'] = 0;
}
if (!isset($_SESSION['attempted'])) {
$attempted = 0;
$_SESSION['attempted'] = 0;
}
$resArray = array();
$resArray['message'] = '';
$resArray['status'] = '';
$no = $_POST['no'];
$postedAnswer = $_POST['answer_'.$no];
$question_id = $_POST['question_id'];
$subject_id = $_POST['subject_id'];
$sql = "SELECT True_answer FROM question WHERE QuestionId = '$question_id' AND SubjectId = '$subject_id'";
$result = mysqli_query($conn, $sql);
$row = mysqli_fetch_assoc($result);
$True_answer = $row['True_answer'];
if($postedAnswer === $True_answer)
{
$result = $_SESSION['result'];
$result++;
$_SESSION['result'] = $result;
}
$attempted = $_SESSION['attempted'];
$attempted++;
$_SESSION['attempted'] = $attempted;
$resArray['status'] = true;
//$resArray['q_id'] = $no;
$resArray['message'] = 'Submitted Successfully';
echo json_encode($resArray);
exit();
}
=====questions.php========
<form action="includes/functions.php" id="question_form_<?php echo $j; ?>" >
<div class='container' >
<div class='row'>
<div class='col-lg-12'>
<div class='thumbnail'>
<p id="question_description">Q.<?php echo $i; ?><br><?php echo $row['QuestionDescription']; ?></p>
<div class="questions_options">
<label><input type="radio" id="btn_radio" name="answer_<?php echo $j; ?>" value="<?php echo $row['Option1']; ?>"><?php echo $row['Option1']; ?></input></label><br>
<label><input type="radio" id="btn_radio" name="answer_<?php echo $j; ?>" value="<?php echo $row['Option2']; ?>"><?php echo $row['Option2']; ?></input></label><br>
<label><input type="radio" id="btn_radio" name="answer_<?php echo $j; ?>" value="<?php echo $row['Option3']; ?>"><?php echo $row['Option3']; ?></input></label><br>
<label><input type="radio" id="btn_radio" name="answer_<?php echo $j; ?>" value="<?php echo $row['Option4']; ?>"><?php echo $row['Option4']; ?></input></label><br><br>
<input type="hidden" name="question_id" value="<?php echo $row['QuestionId'] ?>">
<input type="hidden" name="subject_id" value="<?php echo $row['SubjectId'] ?>">
<input type="hidden" name="question_form" value="question_form">
<input type="hidden" name="no" value="<?php echo $j; ?>">
<button class="btn btn-primary btn-sm" id="btn_submit">Submit<i class="glyphicon glyphicon-arrow-right" >
</i></button>
</div>
</div>
</div>
</div>
</div>
</form>
============result.php===============
<table class="table table-striped table-hover" id="result_table" >
<thead>
<tr>
<th style="text-align: center;">Total Questions</th>
<th style="text-align: center;">Attempted Questions</th>
<th style="text-align: center;">Total Marks</th>
<th style="text-align: center;">Obtained Marks</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: center;"><?php echo $number_of_questions;?></td>
<td style="text-align: center;"><?php echo $_SESSION['attempted']; ?></td>
<td style="text-align: center;"><?php if(!isset($_SESSION['result']))
{
echo "empty";
}
else
{
echo $_SESSION['result'];
}
?></td>
<td style="text-align: center;"><?php echo $marks_obtained;?></td>
</tr>
</tbody>
</table>

Answer 1

Please start the session using session_start() function