随机数 获取当前时间 

var aa = new Date();//生成时间
var aa = Date.now()//以时间生成随机数
var aa = Math.random()//生成0-1之间的小数
var aa = parseInt((Math.random()*10)+20)//生成20-30之间的整数 parseInt //取整
var aa = Math.ceil()//取整向上 var aa = Math.ceil(Math.random()*100)//生成1-100之间的数//取整向上小数 
var aa = Math.round(55.5)//4舍5入 
var aa = Math.round(Math.random()*100)//生成1-100之间的小数4舍5入

 

 







　var arr = []//随机生成20个200-300之间的数字
    for (let i = 0; i < 10; i++) {
    var all= ((Math.random()*100)+200).toFixed(0)
    arr.unshift(all)
      
    }
    console.log(arr)




 






<!doctype html>
<html lang="en">
 <head>
  <meta charset="UTF-8">
  <title>获取当前时间</title>
 </head>
 <body>
  <script type="text/javascript">
    /**
     *获取当前时间
     *format=1精确到天
     *format=2精确到分
     *format=3时间字符串
    */
    function getCurrentDate(format) {
      var now = new Date();
      var year = now.getFullYear(); //得到年份
      var month = now.getMonth();//得到月份
      var date = now.getDate();//得到日期
      var day = now.getDay();//得到周几
      var hour = now.getHours();//得到小时
      var minu = now.getMinutes();//得到分钟
      var sec = now.getSeconds();//得到秒
      month = month + 1;
      if (month < 10) month = "0" + month;
      if (date < 10) date = "0" + date;
      if (hour < 10) hour = "0" + hour;
      if (minu < 10) minu = "0" + minu;
      if (sec < 10) sec = "0" + sec;
      var time = "";
      //精确到天
      if(format==1){
        time = year + "-" + month + "-" + date;
      }
      //精确到分
      else if(format==2){
        time = year + "-" + month + "-" + date+ " " + hour + ":" + minu + ":" + sec;
      }
      //精确到分
      else if(format==3){
        time = year +"" + month  + date + hour  + minu  + sec;
      }
      console.log(time);
      return time;
    }
    alert(getCurrentDate(3));
  </script>
 </body>
</html>




 


 


 








            

            
posted @ 
2020-01-11 17:46 
七月的风* 
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