src/Common/Helper.php
public static function validateLuhn($number)
    {
        $str = '';
        foreach (array_reverse(str_split($number)) as $i => $c) {
            $str .= $i % 2 ? $c * 2 : $c;
        }

        return array_sum(str_split($str)) % 10 === 0;
    }
public static function validateLuhn($number)
    {
        $str = '';
        foreach (array_reverse(str_split($number)) as $i => $c) {
            $str .= $i % 2 ? $c * 2 : $c;
        }

        return array_sum(str_split($str)) % 10 === 0;
    }
Validate a card number according to the Luhn algorithm.

@param  string  $number The card number to validate
@return boolean True if the supplied card number is valid