What are the best practices for handling user input of decimal numbers with commas in PHP applications?

When handling user input of decimal numbers with commas in PHP applications, it is important to first sanitize the input by removing any non-numeric characters and then convert the comma-separated decimal number into a format that PHP can recognize. One way to achieve this is by using the str_replace() function to replace commas with periods before converting the string to a float.

// Get user input with commas in decimal numbers
$userInput = $_POST['decimal_input'];

// Sanitize the input by removing non-numeric characters and replacing commas with periods
$cleanInput = preg_replace("/[^0-9,.]/", "", $userInput);
$cleanInput = str_replace(',', '.', $cleanInput);

// Convert the sanitized input to a float
$decimalNumber = (float) $cleanInput;

// Now $decimalNumber contains the decimal number with commas handled correctly