html中嵌入js为什么不能输出

Question

如下
<a href="/team/buy2.php?id={$one['id']}&is_fox=<script>document.write(is_fox)</script>" class="en-btn" target="_blank">
得到结果：
http://www.xxx.com/team/buy2.php?id=ZTNDczMg==&is_fox=<script>document.write(is_fox)</script>而改成：
<script>document.write("<a href=\"\/team\/buy2.php?id={$one['id']}&is_fox="+is_fox+" class=\"en-btn\" target=\"_blank\">" );</script>可以输出了，但是得到结果：
http://www.xxx.com/team/buy2.php?id=ZTNDczMg==&is_fox=0 class=都是错误的，我想得到
http://www.xxx.com/team/buy2.php?id=ZTNDczMg==&is_fox=0
怎么改

Answer 1

<script>document.write("<a href=\"\/team\/buy2.php?id={$one['id']}&is_fox="+is_fox+"\" target=\"_blank\">" );</script>

Answer 2

http://www.xxx.com/team/buy2.php?id=ZTNDczMg==&is_fox=<script>document.write(is_fox)</script><>()/在URL里面要用转义字符的