private function _parseAttrStringValue(int &$offset): string
    {
        $idx = $offset;
        if ($idx >= $this->_len) {
            return "";
        }
        if ('"' == $this->_dn[$idx]) { // quoted string
            $val = $this->_parseQuotedAttrString($idx);
        } else { // string
            $val = $this->_parseAttrString($idx);
        }
        $offset = $idx;
        return $val;
    }
private function _parseAttrStringValue(int &$offset): string
    {
        $idx = $offset;
        if ($idx >= $this->_len) {
            return "";
        }
        if ('"' == $this->_dn[$idx]) { // quoted string
            $val = $this->_parseQuotedAttrString($idx);
        } else { // string
            $val = $this->_parseAttrString($idx);
        }
        $offset = $idx;
        return $val;
    }
private function _parseAttrStringValue ( int & $ offset ) : string { $ idx = $ offset ; if ( $ idx >= $ this -> _len ) { return "" ; } if ( '"' == $ this -> _dn [ $ idx ] ) { // quoted string $ val = $ this -> _parseQuotedAttrString ( $ idx ) ; } else { // string $ val = $ this -> _parseAttrString ( $ idx ) ; } $ offset = $ idx ; return $ val ; }
Parse 'attributeValue' of string type.

@param int $offset
@throws \UnexpectedValueException
@return string
Parse attributeValue of string type .