How can i make sure there is a certain amount of numbers in a decimal (trailing zeros)

Question

In my website, there are money amounts being echoed. When I subtract from the money amounts, it removes the trailing zero until I log out and log back into my account. Is there a way to check that there are always two numbers after the decimal and add a zero if there isn't?

Here is my php subtraction code:

<?php
session_start();

$servername = "localhost";
$username = "root";
$password = "patrick2002";
$dbname = "accounts";
$cash_amount = $_SESSION['cash_amount'];

// Create connection

$userid = $_SESSION['id'];

// You must enter the user's id here. /\

$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection

if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

// Fetch the existing value of the cash_amount against that particular user here. You can use the SELECT cash_amount from users where userid = $userid
$_SESSION['cash_amount'] -= 0.05;
$newAmount = $cash_amount - 0.05;

$sql = "UPDATE users SET cash_amount = $newAmount WHERE id = $userid";
$result = $conn->query($sql);

if($result)
{
   echo "5 cents has been subtracted!";
}
else
{
   echo mysqli_error($conn);
}

$conn->close();
?>

And here is my php echo code:

<?php echo '$'.$cash_amount ?>

At the beginning of the document:

$cash_amount = $_SESSION['cash_amount'];

So if you could help me, I'd be very very grateful. Thanks guys!

Answer 1

try

echo sprintf('%0.2f', $cash_amount);

Or in you html/php:

...
$<?php echo sprintf('%0.2f', $cash_amount) ?>
...