What are the potential pitfalls of using $_POST['$variable'] instead of assigning it to a variable like $variable = $_POST['variable']?

Using $_POST['$variable'] directly can lead to potential security vulnerabilities such as SQL injection attacks if the input is not properly sanitized. Assigning it to a variable like $variable = $_POST['variable'] allows you to validate and sanitize the input before using it in your code, reducing the risk of security issues.

// Assigning $_POST['$variable'] to a variable and sanitizing the input
$variable = isset($_POST['variable']) ? filter_var($_POST['variable'], FILTER_SANITIZE_STRING) : '';