倒计时5（超过时间为0:0:0） 

<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <title>js简单时分秒倒计时</title>
    <script type="text/javascript">
    function countTime() {
        var timer;
        //获取当前时间  
        var date = new Date();
        var now = date.getTime();
        //设置截止时间  
        var str = "2020/2/8 15:40:00";
        var endDate = new Date(str);
        var end = endDate.getTime();

        //时间差  
        var leftTime = end - now;
        //定义变量 d,h,m,s保存倒计时的时间  
        var d, h, m, s;
        if (leftTime >= 0) {
            d = Math.floor(leftTime / 1000 / 60 / 60 / 24);
            h = Math.floor(leftTime / 1000 / 60 / 60 % 24);
            m = Math.floor(leftTime / 1000 / 60 % 60);
            s = Math.floor(leftTime / 1000 % 60);
            //将倒计时赋值到div中  
            document.getElementById("_d").innerHTML = d + "天";
            document.getElementById("_h").innerHTML = h + "时";
            document.getElementById("_m").innerHTML = m + "分";
            document.getElementById("_s").innerHTML = s + "秒";
        } else {
            //将倒计时赋值到div中  
            document.getElementById("_d").innerHTML = 0 + "天";
            document.getElementById("_h").innerHTML = 0 + "时";
            document.getElementById("_m").innerHTML = 0 + "分";
            document.getElementById("_s").innerHTML = 0 + "秒";
            clearInterval(timer);
        }
    }
    setInterval(countTime, 0); //setInterval() 方法可按照指定的周期（以毫秒计）来调用函数或计算表达式。
    </script>
</head>

<body>
    <div>
        <span id="_d">00</span>
        <span id="_h">00</span>
        <span id="_m">00</span>
        <span id="_s">00</span>
    </div>
</body>

</html>

 

posted @ 2018-02-08 15:42  前端HL  阅读(316)  评论(0)    收藏  举报