Orlando's Grade Calculator

Enter a grade on a 0-100 scale, then press "Add Grade".
Press "Submit" when you are done entering grades.

Enter Grades:

List of Grades:

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CODE FOLLOWS

<?php
include("includes/header.php");
?>

<?php
// code
error_reporting(E_ALL);

echo("<h1>Orlando's Grade Calculator</h1>");

echo('<h2>Enter a grade on a 0-100 scale, then press "Add Grade". 
    <br> Press "Submit" when you are done entering grades.</h2>');

// Add new grade to the array
$newGrade = isset($_POST['newGrade']) ? $_POST['newGrade'] : '';
$step = isset($_POST['step']) ? $_POST['step'] : 0;

// Holds grade data
$grades = [];
if (isset($_POST['grades'])) {
    $grades = explode(',', $_POST['grades']);
}

//
if ($newGrade){
    $newGrade = $_POST['newGrade'];
    $grades[]= $newGrade;
}


// filter browser input
$newGrade = htmlentities($newGrade);
$step = htmlentities($step);
?>

    <form action="DecisionsLoopsDemo.php" method="POST">
        <label for="name">Enter Grades: </label>
        <input type="text" size="36" id="newGrade" name="newGrade" value="">
        <br><br>
        <input type="hidden" name="grades" value="<?= implode(',', $grades) ?>">
        <input type="submit" name="submit" value="Submit">
        <input type="submit" name="addGrade" value="Add Grade">
    </form>

    <?php
    echo("<h3>List of Grades: </h3>");
    foreach ($grades as $grade) {
        echo($grade . ' ');
    }
    ?>

<?php

$studentLetterGrade = null;
if (isset($_POST['submit'])){
    if(count($grades) > 1){
        $coursePercent = round(array_sum($grades) / (count(array_filter($grades))), 2);
        if ($coursePercent < 60) {
            $studentLetterGrade = 'F';
        } elseif ($coursePercent < 70) {
            $studentLetterGrade = 'D';
        } elseif ($coursePercent < 80) {
            $studentLetterGrade = 'C';
        } elseif ($coursePercent < 90) {
            $studentLetterGrade = 'B';
        } else {
            $studentLetterGrade = 'A';
        }
        echo("<h2>This student's course percentage grade is $coursePercent%.<br>
            They have a $studentLetterGrade in the course</h2>");
    }
}
// provide a form to try again
?>
    <br><br>
    <form action="DecisionsLoopsDemo.php" method="POST">
        <input type="hidden" name="grades" value="">
        <input type="submit" name="submit" value="New Student">
    </form>

<?php
include("includes/footer.php");
?>

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