我如何确保十进制中有一定数量的数字（尾随零）

Question

在我的网站上，有金额被回显。当我从金额中减去时，它会删除尾随的零，直到我注销并重新登录我的帐户。有没有办法检查小数点后是否总是有两个数字，如果没有则添加零？

这是我的php减法代码：

<?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();
?>

这是我的 php 回显代码：

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

文档开头：

$cash_amount = $_SESSION['cash_amount'];

所以如果你能帮助我，我将非常非常感激。谢谢大家！

Answer 1

试试

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

或者在你的html/php中：

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