Method tel

/**
 * Converts strings of integers into more readable telephone format
 *
 * By default, the ITU-T format will automatically be used.
 * However, one of the allowed unit types may also be used instead.
 *
 * @param   integer  $number       The integers in a phone number with dot separated country code
 *                                 ccc.nnnnnnn where ccc represents country code and nnn represents the local number.
 * @param   string   $displayplan  The numbering plan used to display the numbers.
 *
 * @return  string  The formatted telephone number.
 *
 * @see     \Joomla\CMS\Form\Rule\TelRule
 * @since   1.6
 */
public static function tel($number, $displayplan)
{
    $number = explode('.', $number);
    $countrycode = $number[0];
    $number = $number[1];
    if ($displayplan === 'ITU-T' || $displayplan === 'International' || $displayplan === 'int' || $displayplan === 'missdn' || $displayplan == null) {
        $display[0] = '+';
        $display[1] = $countrycode;
        $display[2] = ' ';
        $display[3] = implode(' ', str_split($number, 2));
    } elseif ($displayplan === 'NANP' || $displayplan === 'northamerica' || $displayplan === 'US') {
        $display[0] = '(';
        $display[1] = substr($number, 0, 3);
        $display[2] = ') ';
        $display[3] = substr($number, 3, 3);
        $display[4] = '-';
        $display[5] = substr($number, 6, 4);
    } elseif ($displayplan === 'EPP' || $displayplan === 'IETF') {
        $display[0] = '+';
        $display[1] = $countrycode;
        $display[2] = '.';
        $display[3] = $number;
    } elseif ($displayplan === 'ARPA' || $displayplan === 'ENUM') {
        $number = implode('.', str_split(strrev($number), 1));
        $display[0] = '+';
        $display[1] = $number;
        $display[2] = '.';
        $display[3] = $countrycode;
        $display[4] = '.e164.arpa';
    }
    return implode('', $display);
}