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Introducing javascript to implement timer countdown

coldplay.xixiforward: 2021-04-15 17:37:142318browse

Without further ado, let’s get straight to the code.

<!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>
    <p>
        <span class="hour">1</span>
        <span class="minute">2</span>
        <span class="second">3</span>
    </p>
    <script>
        var hour = document.querySelector('.hour'); //小时的黑色盒子
        var minute = document.querySelector('.minute'); //分钟的黑色盒子
        var second = document.querySelector('.second'); //秒数的盒子
        var inputTime = +new Date('2021-4-10 23:00:00'); //返回的是用户输入的时间总的毫秒数
        // 封装好的计算时间的函数
        //先调用一次函数防止开始出现空白
        countDown();
        //开启定时器
        setInterval(countDown,1000);
        function countDown() {
            var nowTime = +new Date(); //返回的是当前时间的走毫秒数
            var times = (inputTime - nowTime) / 1000; //times是剩余时间的总数
            // var d = parseInt(times / 60 / 60 / 24); //天
            // d = d < 10 ? &#39;0&#39; + d : d;
            var h = parseInt(times / 60 / 60 % 24); //时
            h = h < 10 ? &#39;0&#39; + h : h;
            hour.innerHTML = h; //把剩余的小时给小时黑盒子
            var m = parseInt(times / 60 % 60); //当前秒
            m = m < 10 ? &#39;0&#39; + m : m;
            minute.innerHTML = m;//把剩余的分钟给盒子
            var s =parseInt(times%60);//当前秒
            s = s < 10 ? &#39;0&#39; + s : s;
            second.innerHTML = s;//把剩余的秒数给盒子
            // return d + &#39;天&#39; + h + &#39;时&#39; + m + &#39;分&#39; + s + &#39;秒&#39;;
        }
    </script></body></html>

A time conversion function is encapsulated here:

 function countDown() {
            var nowTime = +new Date(); //返回的是当前时间的走毫秒数
            var times = (inputTime - nowTime) / 1000; //times是剩余时间的总数
            var d = parseInt(times / 60 / 60 / 24); //天
            d = d < 10 ? '0' + d : d;
            var h = parseInt(times / 60 / 60 % 24); //时
            h = h < 10 ? '0' + h : h;
            var m = parseInt(times / 60 % 60); //当前秒
            m = m < 10 ? '0' + m : m;
            var s =parseInt(times%60);//当前秒
            s = s < 10 ? '0' + s : s;
         	return d + '天' + h + '时' + m + '分' + s + '秒';
        }

Related Free learning recommendations: javascript learning tutorial

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