<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>JS基础</title>
<script type="text/javascript">
var a,b,sum;
var a = 5;
var b = 100%7;
sum = a > b ;
document.write( "我认为 a 的值是:" + a + " b的值是:" + b + "sum 的值是:" +sum+"<br/>");
sum = ( (++a) + 3 ) / (2 - (--b) ) * 3;
document.write("sum的值是："+27);
document.write("答案是："+sum+"<br/>");
/*var array=new Array(10);
array=[1,2,3,4,5,6,7,8,9,10,11];*/
var array=[1,2,3,4,5];
document.write("数组的长度为"+array.length+"<br>");
for(i=0;i<5;i++)
{
document.write((array[i])+"<br/>");
}
var myarr=new Array();
for(var i=0;i<3;i++)
{ myarr[i]=new Array();
for(var n=0;n<6;n++)
{
myarr[i][n]=i*n;
}
}
document.write(myarr);
var arr=['*','**','***'];
alert("该数组的长度为："+arr.length);
for(var j=0;j<3;j++);
{
document.write(arr[j]);
}
var myweek=3;
switch(myweek)
{
case 1:
case 2:
document.write("学习理念知识");
break;
case 3:
case 4:
document.write("到企业实践");
break;
case 5:
document.write("总结经验");
break;
case 6:
case 7:
document.write("周六、日休息和娱乐");
default;
}
</script>
</head>
</html>可是我运行的时候var arr=['*','**','***'];这个数组显示出来的结果是undefined，我明明给它赋值了。
default:;