<?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);
    }
}

• [F] Ean.php
  Delete
• [F] Iban.php
  Delete
• [F] Inn.php
  Delete
• [F] Isbn.php
  Delete
• [F] Luhn.php
  Delete
• [F] TCNo.php
  Delete

Blog Section

Discover the Latest in Digital Payments and NFC Technology

Dive into our blog to explore the cutting-edge trends in digital payments and NFC technology. Stay updated on the innovations that are revolutionizing transactions, boosting security, and making payments quicker and more convenient. Learn how these advancements are shaping the future of financial interactions and driving the global transition towards a cashless world.

The Rise of Contactless Payments:...

In recent years, contactless payments have surged in popularity, driven...

Visit Blog

March 27, 2024

Enhancing Payment Security: The Role...

As digital transactions proliferate, ensuring robust payment security is more critical than ever. Two foundational...

Visit Blog

March 27, 2024

The Future of Digital Wallets:...

Digital wallets have fundamentally transformed how we manage money, offering a streamlined, secure, and highly...

Visit Blog

March 27, 2024