JavaScript日期对象(Date)基本用法示例

时间:2020-05-15 books1958 人气:0

本文实例讲述了JavaScript日期对象(Date)基本用法。分享给大家供大家参考，具体如下：

1.获取当前日期：

document.write("Current time: "+new Date());

2.获取时间戳（毫秒）：

document.write(new Date().getTime());

3.设置年月日（年为必选，月日为可选）：

var d = new Date();
d.setFullYear(2016,3,16)
document.write(d);
document.write("<br/>");
document.write(d.getTime());

4.返回当前星期几：

document.write(new Date().getDay())

5.日期对象的比较：

function compareDate(){
  var oneday = new Date();
  oneday.setFullYear(2016,2,26);
  var currentday = new Date();
  if (oneday<currentday){
   alert("before");
  }else{
   alert("after");
  }
}

效果图：

示例代码：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta http-equiv="Content-Language" content="zh-cn" />
<title>Javascript 日期对象</title>
<head>
 <style>
  body {background-color:#e6e6e6}
 </style>
</head>
<body onload="startTime()">
 <h3>（一）返回当前的日期</h3>
 <script>
 document.write("Current time: "+new Date());
 </script>
 <h3>（二）返回时间戳（毫秒）</h3>
 <script>
 document.write(new Date().getTime());
 </script>
 <h3>（三）设置年月日</h3>
 <script>
 var d = new Date();
 d.setFullYear(2016,3,16)
 document.write(d);
 document.write("<br/>");
 document.write(d.getTime());
 </script>
 <h3>（四）将当日的日期（根据 UTC）转换为字符串</h3>
 <script>
 var d2 = new Date()
 document.write (d2.toUTCString())
 </script>
 <h3>（五）返回当前星期几</h3>
 <script>
 var d3=new Date()
 var weekday=new Array(7)
 weekday[0]="星期日"
 weekday[1]="星期一"
 weekday[2]="星期二"
 weekday[3]="星期三"
 weekday[4]="星期四"
 weekday[5]="星期五"
 weekday[6]="星期六"
 document.write(weekday[d3.getDay()])
 </script>
 <h3>（六）显示一个时间钟表</h3>
 <p id = "time_text"></p>
 <script>
  function startTime(){
   var today = new Date();
   var y = today.getFullYear();
   var M = today.getMonth()+1;
   var day = today.getDay();
   var h = today.getHours();
   var m = today.getMinutes();
   var s = today.getSeconds();
   m = checkTime(m);
   s = checkTime(s);
   var content = (y+"/"+M+"/"+day+" "+h+":"+m+":"+s).fontsize(6).fontcolor("red");
   document.getElementById("time_text").innerHTML = content;
   setTimeout("startTime()",500);
  }
  function checkTime(i){
   if(i<10){
    return "0"+i;
   }
   return i;
  }
 </script>
 <h3>（七）日期对象的比较</h3>
 <p>2016.3.26与当前时间的关系？</p>
 <button onclick = "compareDate()">比较</button>
 <script>
 function compareDate(){
  var oneday = new Date();
  oneday.setFullYear(2016,2,26);
  var currentday = new Date();
  if (oneday<currentday){
   alert("before");
  }else{
   alert("after");
  }
 }
 </script>
</body>
</html>

PS：这里再为大家推荐几款时间及日期相关工具供大家参考使用：

在线秒表工具：
http://tools.softyun.net/bianmin/miaobiao

Unix时间戳(timestamp)转换工具：
http://tools.softyun.net/code/unixtime

在线世界各地时间查询：
http://tools.softyun.net/zhuanhuanqi/worldtime

希望本文所述对大家JavaScript程序设计有所帮助。

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