Issue retrieving data from DB due to undefined variable - php

Question

My intention is to retrieve data from a database and have created the following functions but receive an undefined function, grades, error message. The code is as follows:
<form action="processor.php" method="post">
<h4>Question # 1</h4>
<p>What grade are you in?</p>
<label class="checkbox"><input type="checkbox" name="grade" value="1"> Freshmen</label>
<label class="checkbox"><input type="checkbox" name="grade" value="2"> Sophomore</label>
<label class="checkbox"><input type="checkbox" name="grade" value="3"> Junior</label>
<label class="checkbox"><input type="checkbox" name="grade" value="4"> Senior</label>
<h4>Question # 2</h4>
<p>What is your current GPA?</p>
<select name="gpa">
<option value="4">3.5 or above</option>
<option value="3">3.0-3.4</option>
<option value="2">2.5-2.9</option>
<option value="1">2.0-2.4</option>
<option value="0">Lower</option>
</select>
<h4>Question # 3</h4>
<p>Where do you excel the most academically?</p>
<select name="school" multiple="multiple">
<option value ="1">Mathematics</option>
<option value ="2">Literature</option>
<option value ="3">History</option>
<option value ="4">Humanities</option>
<option value ="5">Science</option>
</select>
Then the PHP file that processes the form submission:
<?php
require_once('processor.php');
class Processor {
#code
function get_response($id) {
$dsn = "mysql:host=localhost;dbname=user";
$username = "root"; // database username
$password = "stewie12"; // database password
try {
$enter = new PDO($dsn, $username, $password);
$sql = "SELECT response FROM recommendations WHERE id = ? ";
$new_item = $enter->prepare($sql);
$new_item->setFetchmode(PDO::FETCH_ASSOC);
$new_item->execute(array($id));
foreach($new_item as $nw) {
return $nw['response'];
}
} catch (Exception $e) {
echo $e->getMessage();
exit;
}
return "";
}
function GetWeird () {
$santiago="1992";
if ($santiago="1992") {
$id = 1;
} else {
$id = 2;
}
echo $this->get_response($id);
}
function Grades () {
$grade = $_POST['grade'];
if ($grade =="1") {
echo "You're a freshmen";
} elseif ($grade == "2") {
echo "You're a sophomore";
} elseif ($grade == "3") {
echo "You're a junior.";
} elseif ($grade == "4") {
echo "You're a senior.";
} else {
echo "Something is wrong.";
}
}
function Gpa () {
$gpa = $_POST['gpa'];
if ($gpa =="1") {
echo "You strongly need to up your GPA.";
} elseif ($gpa == "2") {
echo "You're an average student.";
} elseif ($gpa == "3") {
echo "You're an above average student.";
} elseif ($gpa == "4") {
echo "You're an excellent sudent.";
} else {
echo "Something is wrong.";
}
}
function School () {
$school = $_POST['school'];
if ($school =="1") {
echo "You're into Math";
} elseif ($school == "2") {
echo "You're into Lit";
} elseif ($school == "3") {
echo "You're into history.";
} elseif ($school == "4") {
echo "You're into humanities.";
} elseif ($school == "5") {
echo "You're into science.";
} else {
echo "Something is wrong.";
}
}
And the view page:
<?php $processor = new Processor(); ?>
<h4>Question # 1</h4>
<p><?php Grades($grade); ?></p>
<h4>Question # 2</h4>
<p><?php Gpa($gpa); ?></p>
<h4>Question # 3</h4>
<p><?php School($school); ?></p>

Answer 1

To access the class function use below code,
You have to use it like this $class_variable->function_name()
<?php $processor = new Processor(); ?>
<h4>Question # 1</h4>
<p><?php $processor->Grades($grade); ?></p>
<h4>Question # 2</h4>
<p><?php $processor->Gpa($gpa); ?></p>
<h4>Question # 3</h4>
<p><?php $processor->School($school); ?></p>