window.onload=setInterval(datestr,1000);
function datestr(){
var date = new Date();
var weekday=["星期日","星期一","星期二","星期三","星期四","星期五","星期六"];
var datestr = "当前日期:"+date.getFullYear()+"年"+((Number(date.getMonth()+1)<10 ? ("0"+(date.getMonth()+1)):(date.getMonth()+1)))+"月"+(Number(date.getDate()) <10 ? "0"+date.getDate():date.getDate())+"日 "+weekday[date.getDay()]+" "+((Number(date.getHours()+1)<10?("0"+(date.getHours()+1)):(date.getHours()+1)))+"时"+((Number(date.getMinutes()+1)<10?("0"+(date.getMinutes()+1)):(date.getMinutes()+1)))+"分"+((Number(date.getSeconds()+1)<10?("0"+(date.getSeconds()+1)):(date.getSeconds()+1)))+"秒";
//方法二:使用switch-case语句
/*switch(date.getDay()){
case 0:
datestr += " 星期日";
break;
case 1:
datestr += " 星期一";
break;
case 2:
datestr += " 星期二";
break;
case 3:
datestr += " 星期三";
break;
case 4:
datestr += " 星期四";
break;
case 5:
datestr += " 星期五";
break;
case 6:
datestr += " 星期六";
break;
}*/
var adv=document.getElementById("dateshow");
adv.innerHTML=datestr;
}
效果: