var str = "";  var week = new Date().getDay();  if (week == 0) {          str = "今天是星期日";  } else if (week == 1) {          str = "今天是星期一";  } else if (week == 2) {          str = "今天是星期二";  } else if (week == 3) {          str = "今天是星期三";  } else if (week == 4) {          str = "今天是星期四";  } else if (week == 5) {          str = "今天是星期五";  } else if (week == 6) {          str = "今天是星期六";  }   name="code" class="javascript">    alert(str);</pre> 

  var str = "今天是星期";  var week = new Date().getDay();  switch (week) {          case 0 :                  str += "日";                  break;          case 1 :                  str += "一";                  break;          case 2 :                  str += "二";                  break;          case 3 :                  str += "三";                  break;          case 4 :                  str += "四";                  break;          case 5 :                  str += "五";                  break;          case 6 :                  str += "六";                  break;  }  alert(str); 

  var a = new Array("日", "一", "二", "三", "四", "五", "六");  var week = new Date().getDay();  var str = "今天是星期"+ a[week];  alert(str); 

var str = "今天是星期" + "日一二三四五六".charAt(new Date().getDay());alert(str);