JavaScript实现指定秒数后自动跳转页面的方法

 <div class="box">
        <h3>支付成功</h3>
        <a href="https://blog.csdn.net/Quentin0823/article/details/123184824?spm=1001.2014.3001.5502" rel="external nofollow" >
            <span id="num">3</span>
            <span>秒后自动跳转</span>
        </a>
    </div>

<script>
        function jump() {
            var time = document.getElementById('num');
            var _num = time.innerHTML;
            if (_num > 0) {
                _num--;
                time.innerHTML = _num;
            } else {
                location.assign("https://blog.csdn.net/Quentin0823/article/details/123184824?spm=1001.2014.3001.5502")
            }
        }
        setInterval(jump, 1000)
    </script>

<!DOCTYPE html>
<html lang="en">
 
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
 
<body>
    <button>跳转百度</button>
    <div></div>
 
    <script>
        var btn = document.querySelector('button');
        var div = document.querySelector('div')
            btn.addEventListener('click', function() {
                var times = 5;
                setInterval(function() {
                    if (times == 0) {
                        location.href = 'http://www.baidu.com';
                        times = 5;
                    } else {
                        div.innerHTML = '还剩' + times + '秒自动跳转'
                        times--;
                    }
 
            }, 1000)
        })
        // 五秒后直接跳转
        var times = 5
        setInterval(function() {
            if (times == 0) {
                location.href = 'http://www.baidu.com';
                times = 5;
            } else {
                div.innerHTML = '还剩' + times + '秒自动跳转'
                times--;
            }
 
        }, 1000)
    </script>
</body>
 
</html>