createa("http://www.imooc.com/","慕课网");?? createa为什么这样输出？而不是document.write(createa)
<script type="text/javascript">
var main = document.body;
var body= document.body;
//创建链接
function createa(url,text)
{
var a = document.createElement("a");
a.href = url;
a.innerHTML = text;
a.style.color = "red";
body.appendChild(a);
}
// 调用函数创建链接
createa("http://www.imooc.com/","慕课网");
</script>
