用js实现一个数字时钟

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Digital Clock</title>
    <style>
        #clock {
            font-size: 48px;
            text-align: center;
            margin-top: 50px;
        }
    </style>
</head>
<body>
    <div id="clock"></div>

    <script>
        function updateClock() {
            const now = new Date();
            const hours = String(now.getHours()).padStart(2, '0');
            const minutes = String(now.getMinutes()).padStart(2, '0');
            const seconds = String(now.getSeconds()).padStart(2, '0');
            const timeString = `${hours}:${minutes}:${seconds}`;
            document.getElementById('clock').textContent = timeString;
        }

        // 初始更新
        updateClock();

        // 每秒更新一次
        setInterval(updateClock, 1000);
    </script>
</body>
</html>