【PHP】個人資料隱碼 程式碼

設定字串欲隱藏的前後位置，並取代為指定字符

function replaceSymbol($string, $symbol, $start = 0, $end = 0)
    {
        $length = mb_strlen($string);
        if ($length === 0) {
            return '';
        }

        $start = (int) $start;
        $end   = (int) $end;
        $mid   = (int) $length - $start - $end;
        if ($mid <= 0) {
            return $string;
        }

        $startWord = mb_substr($string, 0, $start);
        $endWord   = ($end === 0) ? '' : mb_substr($string, 0 - $end);
        $midWord   = str_repeat($symbol, $mid);
        return $startWord . $midWord . $endWord;
    }