- <script language="javascript">
- <!--
- var r=prompt("输入圆的半径"."0");
- if(r!=null)
- {
- var square=r*r*Math.PI;
- document.write("圆的面积为:"+square);
- }
- else
- {
- alert(”输入数据有误“)
- }
- -->
- </script>
- //该片段来自于http://www.codesnippet.cn/detail/130920135873.html
来源: http://www.codesnippet.cn/detail/130920135873.html