Make tel: anchor tags from telephones string

telLinkTag.php

function telLinkTag($str = '') {
    $delimeter = ', ';
    $tels = explode($delimeter, $str);
    $res = array();
    foreach($tels as $tel) {
        $invalidChar = array('(', ')', ' ', '-');
        array_push($res, '<a href="' .
                            'tel:+' . str_replace($invalidChar, '', $tel) .
                            '">' .
                            $tel .
                            '</a>');
    }
    return implode($delimeter, $res);
}