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);