<script type="text/javascript">
var mynum =6;//mynum初值化数值为6
do
{
document.write("数字:"+mynum+"<br/>");
mynum=mynum-1;
}
while(mynum == 0)
</script>
</head>
while(mynum == 0)相当于布尔类型判断,false,条件为假不能成立,所以跳出循环
while(!(mynum==0))