如何用正则来实现URL中的替换？？？

Question

乱写一个
<script>
var str = "http://msdn.microsoft.com/library/default.asp";
var re = /http:\/\/(.[^\/]+)(\/.+)?/;
alert(str.replace(re,"$1"));
</script>

Answer 1

<script language="javascript">
var url="http://www.china.com/replace/netspace/imgview.html"
var s
s=url.replace(/www.china.com/gi,"123.456.com")
document.write(s)
</script>不是太懂正则....

Answer 2

按照 stefli((桂电)) 所写的可以这样
<script language="javascript">
var url="http://www.china.com/replace/netspace/imgview.html"
var re = /http:\/\/(.[^\/]+)(\/.+)?/;
var s=url.replace(re,"$1");
var s2=url.replace(s,"123.456.com")
document.write(s2)
</script>

Answer 3

不用正则就行了
str.replace("www.china.com","123.456.com");

Answer 4

也在学习，请 s1ihome(I Believe I Can Fly) 帮忙注释一下第3、4、5行。谢谢了