摘要：
天：“0”+天；125//4.使用差值%24的总秒/小时；126lethour=数学。地板127小时=小时˃=10？
1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <title>js京东秒杀</title> 6 7 <style> 8 * { 9 margin: 0; 10 padding: 0; 11 } 12 13 .box { 14 190px; 15 height: 270px; 16 text-align: center; 17 margin: 100px auto; 18 background: #dd0000; 19 color: white; 20 padding-top: 40px; 21 box-sizing: border-box; 22 } 23 24 .box > h3 { 25 font-size: 26px; 26 } 27 28 .box > p:nth-of-type(1) { 29 margin-top: 5px; 30 color: rgba(255, 255, 255, 0.5); 31 } 32 33 .box > i { 34 display: inline-block; 35 margin-top: 5px; 36 margin-bottom: 5px; 37 font-size: 40px; 38 } 39 40 .box > .time { 41 margin-top: 10px; 42 display: flex; 43 justify-content: center; 44 } 45 46 .time > div { 47 40px; 48 height: 40px; 49 line-height: 40px; 50 text-align: center; 51 font-weight: bold; 52 background: #333; 53 position: relative; 54 } 55 56 .time > .minute { 57 margin: 0 10px; 58 } 59 60 .time > div::before { 61 content: ""; 62 display: block; 63 100%; 64 height: 2px; 65 background: #d00; 66 position: absolute; 67 left: 0; 68 top: 50%; 69 transform: translateY(-50%); 70 } 71 </style> 72 <link rel="stylesheet" href="http://t.zoukankan.com/fonts/iconfont.css"> 73 </head> 74 <body> 75 <div class="box"> 76 <h3>京东秒杀</h3> 77 <p>FLASH DEALS</p> 78 <i class="iconfont icon-lightningbshandian"></i> 79 <p>本场距离结束还剩</p> 80 <div class="time"> 81 <div class="hour"></div> 82 <div class="minute"></div> 83 <div class="second"></div> 84 </div> 85 </div> 86 <script> 87 //1.获取到需要操作的元素 88 let oHour = document.querySelector(".hour"); 89 let oMinute = document.querySelector(".minute"); 90 let oSecond = document.querySelector(".second"); 91 92 //2.获取时间的差值 93 let remDate = new Date("2020-3-14 22:00:00"); 94 setTime(remDate);//设置初始化时间 95 //4.利用定时器实现倒计时 96 setInterval(function () { 97 setTime(remDate); 98 }, 1000); 99 100 /** 101 * 3.将差值设置给元素 102 */ 103 function setTime(remDate) { 104 let obj = getDifferTime(remDate); 105 oHour.innerText = obj.hour; 106 oMinute.innerText = obj.minute; 107 oSecond.innerText = obj.second; 108 } 109 110 111 /** 112 * 获得时间差值 113 * @param remDate 未来的时间 114 * @param curDate 当前的时间 115 * @returns {{hour: any | number, day: any | number, minute: any | number, second: any | number}} 116 */ 117 function getDifferTime(remDate, curDate = new Date()) { 118 // 1.得到两个时间之间的差值(毫秒) 119 let differTime = remDate - curDate; 120 // 2.得到两个时间之间的差值(秒) 121 let differSecond = differTime / 1000; 122 // 3.利用相差的总秒数 / 每一天的秒数 = 相差的天数 123 let day = Math.floor(differSecond / (60 * 60 * 24)); 124 day = day >= 10 ? day : "0" + day; 125 // 4.利用相差的总秒数 / 小时 % 24; 126 let hour = Math.floor(differSecond / (60 * 60) % 24); 127 hour = hour >= 10 ? hour : "0" + hour; 128 // 5.利用相差的总秒数 / 分钟 % 60; 129 let minute = Math.floor(differSecond / 60 % 60); 130 minute = minute >= 10 ? minute : "0" + minute; 131 // 6.利用相差的总秒数 % 秒数 132 let second = Math.floor(differSecond % 60); 133 second = second >= 10 ? second : "0" + second; 134 return { 135 day: day, 136 hour: hour, 137 minute: minute, 138 second: second, 139 } 140 } 141 </script> 142 </body> 143 </html>