String "</script>" causes an error in IE

Question

If I add this piece of html to my page:

<script type="text/javascript">
 var s = '</script>'
</script>

IE 7.0 shows a syntax error (exclamation mark in left bottom corner): "Unterminated string constant"

if I change just one letter (any) the error disappears - looks like IE doesn't like this particular word, including brackets.

Any ideas why?

Thank you, Andrey

Answer 1

I've seen this...

var s = '</scr' + 'ipt>'

That said, it gives off a bit of a code smell. I'm not sure if it's appropriate. :)

Answer 2

This will happen for any browser. The HTML parser does not know the details of the scripting language you're trying to use, so your <script> tag will be terminated on the first occurence of </script>, regardless of context. The JS parser will then of course complain that the string is not terminated, because the closing apostrophe is not inside the script block.

You need to use something like '<\/script>' instead if you want to use that scring in your script.

Answer 3

This works for me

var a = "<\/script>"

Answer 4

To use a / character you need to first preface it with \.

So this works:

<script type="text/javascript"> var s = '<\/script>'; alert( s);</script>

Answer 5

I've seen this:

var s = unescape("%3C/script%3E")

Smells really bad too.