Functions to validate Portuguese Citizen Card, JavaScript and PHP

ValidatePortugueseCitizenCard.js

const validator = {

    /**
     * Validates Portuguese citizen card
     * @param {string} value For example 15697354 5 ZZ1
     * @returns {boolean}
     */
    portugueseCitizenCard: function (value) {
        const letterValue = {
            A: 10, B: 11, C: 12, D: 13, E: 14, F: 15, G: 16, H: 17, I: 18, J: 19,
            K: 20, L: 21, M: 22, N: 23, O: 24, P: 25, Q: 26, R: 27, S: 28, T: 29,
            U: 30, V: 31, W: 32, X: 33, Y: 34, Z: 35
        };

        let ccNumber = value.replace(/-|\s/g, '');
        ccNumber = ccNumber.toUpperCase();
        ccNumber = ccNumber.split('').reverse();
        ccNumber[1] = letterValue[ccNumber[1]];
        ccNumber[2] = letterValue[ccNumber[2]];

        let sum = 0;
        for (let i = 0; i < ccNumber.length; i++) {
            let dum = 0;
            if (i % 2 === 0) {
                dum = parseInt(ccNumber[i], 10);
            } else {
                dum = parseInt(ccNumber[i], 10) * 2;
                if (dum >= 10) {
                    dum -= 9;
                }
            }
            sum += dum;
        }

        return sum % 10 === 0;
    },
};

// validator.portugueseCitizenCard("15697354-5-ZZ1") 
// validator.portugueseCitizenCard("15697354 5 ZZ1") 

ValidatePortugueseCitizenCard.php

<?php

/**
 * Validates citizen card
 * @param {string} value For example 15697354 5 ZZ1
 * @returns {boolean}
 */
function portugueseCitizenCard($number)
{
    $letterValue = array(
        'A' => 10, 'B' => 11, 'C' => 12, 'D' => 13, 'E' => 14, 'F' => 15, 'G' => 16, 'H' => 17, 'I' => 18, 'J' => 19,
        'K' => 20, 'L' => 21, 'M' => 22, 'N' => 23, 'O' => 24, 'P' => 25, 'Q' => 26, 'R' => 27, 'S' => 28, 'T' => 29,
        'U' => 30, 'V' => 31, 'W' => 32, 'X' => 33, 'Y' => 34, 'Z' => 35
    );

    $ccNumber = preg_replace('/[-\s]/', '', $number);
    $ccNumber = strtoupper($ccNumber);
    $ccNumber = str_split(strrev($ccNumber));
    $ccNumber[1] = $letterValue[$ccNumber[1]];
    $ccNumber[2] = $letterValue[$ccNumber[2]];

    $sum = 0;
    foreach ($ccNumber as $key => $value) {
        $dum = 0;
        if ($key % 2 === 0) {
            $dum = intval($value);
        } else {
            $dum = intval($value) * 2;
            if ($dum >= 10) {
                $dum -= 9;
            }
        }
        $sum += $dum;
    }

    return $sum % 10 === 0;
}

// var_dump(portugueseCitizenCard('15697354-5-ZZ1'));
// var_dump(portugueseCitizenCard('15697354 5 ZZ1'));