Developer
<?php
namespace Faker\Calculator;
class Iban
{
/**
* Generates IBAN Checksum
*
* @return string Checksum (numeric string)
*/
public static function checksum(string $iban)
{
// Move first four digits to end and set checksum to '00'
$checkString = substr($iban, 4) . substr($iban, 0, 2) . '00';
// Replace all letters with their number equivalents
$checkString = preg_replace_callback(
'/[A-Z]/',
static function (array $matches): string {
return (string) self::alphaToNumber($matches[0]);
},
$checkString,
);
// Perform mod 97 and subtract from 98
$checksum = 98 - self::mod97($checkString);
return str_pad($checksum, 2, '0', STR_PAD_LEFT);
}
/**
* Converts letter to number
*
* @return int
*/
public static function alphaToNumber(string $char)
{
return ord($char) - 55;
}
/**
* Calculates mod97 on a numeric string
*
* @param string $number Numeric string
*
* @return int
*/
public static function mod97(string $number)
{
$checksum = (int) $number[0];
for ($i = 1, $size = strlen($number); $i < $size; ++$i) {
$checksum = (10 * $checksum + (int) $number[$i]) % 97;
}
return $checksum;
}
/**
* Checks whether an IBAN has a valid checksum
*
* @return bool
*/
public static function isValid(string $iban)
{
return self::checksum($iban) === substr($iban, 2, 2);
}
}
Developer
To ensure a smooth integration process and optimal performance, follow these best practices: