js得到本周和下周的日期（在線等）

Question

<script language="JavaScript">
  dayObj=new Date(); 
   monthStr=dayObj.getMonth()+1; 
    if(dayObj.getYear()<99)year2000=2000+dayObj.getYear(); 
 else year2000=dayObj.getYear(); 
  document.write("今天是"+year2000+"年"+monthStr+"月"+dayObj.getDate()+"日"+" "); 
  document.write("<br />")
  var a,b;
   if(dayObj.getDay()==1) {a=(dayObj.getDate()-2) ;b=(dayObj.getDate()+4); }  
   if(dayObj.getDay()==2) {a=(dayObj.getDate()-3) ;b=(dayObj.getDate()+3); }
   if(dayObj.getDay()==3) {a=(dayObj.getDate()-4) ;b=(dayObj.getDate()+2); }
   if(dayObj.getDay()==4) {a=(dayObj.getDate()-5) ;b=(dayObj.getDate()+1); }
   if(dayObj.getDay()==5) {a=(dayObj.getDate()-6) ;b=(dayObj.getDate()+0); }
   if(dayObj.getDay()==6) {a=(dayObj.getDate()) ;b=(dayObj.getDate()+6); }
if(dayObj.getDay()==0) {a=(dayObj.getDate()-1) ;b=(dayObj.getDate()+5); }
if(a<0 )
{
a=""+(monthStr-1)+"月"+(30+a);//需要严正月份的大小
}
if(b>30)
{
b=""+(monthStr+1)+"月"+(b-30);//需要严正月份的大小
}
   document.write("本周的日期是"+a+"-"+b)
</SCRIPT>

Answer 1

  <script   language=javascript>   
  var WeekDays=new Array("星期日","星期一","星期二","星期三","星期四","星期五","星期六")
  var   a=new   Date();
  b=a.getDate();
  b=b-a.getDay();
  
  var ThisWeekFirstDay=new Date();
  ThisWeekFirstDay.setDate(b);   //本周第一天
  var ThisWeekLastDay=new Date();
  ThisWeekLastDay.setDate(b+6);;    //本周最后一天
  var NextWeekFirstDay=new Date();
  NextWeekFirstDay.setDate(b+7);;    //下周第一天
  var NextWeekLastDay=new Date();
  NextWeekLastDay.setDate(b+13);;    //下周最后一天  alert("本周："+ThisWeekFirstDay.toDateString()+" - "+ThisWeekLastDay.toDateString()+"\r\n下周："+ NextWeekFirstDay.toDateString()+" - "+NextWeekLastDay.toDateString());  
  
  </script>