<!DOCTYPE html>
<html>
<head>
<title>Program to calculate electricity bill in PHP</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>
</head>
<body>
<?php
$amount = '';
$kwh_usage = '';
if (isset($_POST['submit'])) {
$units = $_POST['kwh'];
if (!empty($units)) {
$kwh_usage = calculate_electricity_bill($units);
$amount = '<strong>Total amount of ' . $units . ' units -</strong> ' . $kwh_usage;
}
}
/**
* To calculate electricity bill as per unit cost
*/
function calculate_electricity_bill($units) {
$first_unit_cost = 8;
$second_unit_cost = 12;
$third_unit_cost = 16;
$fourth_unit_cost = 20;
if($units <= 100) {
$bill = $units * $first_unit_cost;
}
else if($units > 100 && $units <= 200) {
$temp = 100 * $first_unit_cost;
$remaining_units = $units - 100;
$bill = $temp + ($remaining_units * $second_unit_cost);
}
else if($units > 200 && $units <= 300) {
$temp = (100 * $first_unit_cost) + (100 * $second_unit_cost);
$remaining_units = $units - 200;
$bill = $temp + ($remaining_units * $third_unit_cost);
}
else {
$temp = (100 * $first_unit_cost) + (100 * $second_unit_cost) + (100 * $third_unit_cost);
$remaining_units = $units - 300;
$bill = $temp + ($remaining_units * $fourth_unit_cost);
}
return number_format((float)$bill, 2, '.', '');
}
?>
<div class="container">
<h1>Calculate electricity bill in PHP</h1>
<div class="form-group">
<form action="" method="post">
<div class="form-group">
<input type="number" name="kwh" placeholder="Please enter no. of Units" class="form-control" />
</div>
<div class="form-group">
<input type="submit" name="submit" class="btn btn-primary" value="Submit" />
</div>
</form>
</div>
<div>
<?php echo '<br />' . $amount; ?>
</div>
</div>
</body>
</html><!DOCTYPE html>
<html>
<head>
<title>Program to calculate electricity bill in PHP</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>
</head>
<body>
<?php
$amount = '';
$kwh_usage = '';
if (isset($_POST['submit'])) {
$units = $_POST['kwh'];
if (!empty($units)) {
$kwh_usage = calculate_electricity_bill($units);
$amount = '<strong>Total amount of ' . $units . ' units -</strong> ' . $kwh_usage;
}
}
/**
* To calculate electricity bill as per unit cost
*/
function calculate_electricity_bill($units) {
$first_unit_cost = 8;
$second_unit_cost = 12;
$third_unit_cost = 16;
$fourth_unit_cost = 20;
if($units <= 100) {
$bill = $units * $first_unit_cost;
}
else if($units > 100 && $units <= 200) {
$temp = 100 * $first_unit_cost;
$remaining_units = $units - 100;
$bill = $temp + ($remaining_units * $second_unit_cost);
}
else if($units > 200 && $units <= 300) {
$temp = (100 * $first_unit_cost) + (100 * $second_unit_cost);
$remaining_units = $units - 200;
$bill = $temp + ($remaining_units * $third_unit_cost);
}
else {
$temp = (100 * $first_unit_cost) + (100 * $second_unit_cost) + (100 * $third_unit_cost);
$remaining_units = $units - 300;
$bill = $temp + ($remaining_units * $fourth_unit_cost);
}
return number_format((float)$bill, 2, '.', '');
}
?>
<div class="container">
<h1>Calculate electricity bill in PHP</h1>
<div class="form-group">
<form action="" method="post">
<div class="form-group">
<input type="number" name="kwh" placeholder="Please enter no. of Units" class="form-control" />
</div>
<div class="form-group">
<input type="submit" name="submit" class="btn btn-primary" value="Submit" />
</div>
</form>
</div>
<div>
<?php echo '<br />' . $amount; ?>
</div>
</div>
</body>
</html>