“Uncaught SyntaxError: Unexpected token ?” in both JSON.parse() and $.parseJSON()

Question

I have no idea why I am getting this and I have spent over a day trying to mess with the code. Now the simplest I can get is this (Trying to build a javascript array with an escaped string coming from a database):

vat test = '["<script>var bob = \\"This is ok\\"</script>", "<script>search.replace(/!|\\\?)/g, \\"\\")</script>"]';

So far, so good.

Then this breaks and returns the error:

JSON.parse(test);

To give an idea, the original 2 array items were this:

<script>var bob = "This is ok"</script>
<script>search.replace(/!|\?)/g, "")</script>

All the codes of any kind that were entered in the database have always worked, except now, because of that question mark from a user-entered line in my CMS. If I remove it or replace the question mark by anything else, it works.

I cannot change the regex so to make it work any other way, I am not the one who entered this. Plus this is a simplified version of a whole script, I just narrowed it to the question mark.

I also looked online if the question mark had a special meaning for json, did not find anything.

I wish I could have sent a fiddle instead of just code, but jsfiddle doesn't let me add the tag in the javascript window.

Answer 1

JSON.parse('["<script>var bob = \\"This is ok\\"</script>", "<script>search.replace(/!|\\\?)/g, \\"\\")</script>"]')
SyntaxError: Unexpected token ?

There are two unescapes going on here, so you need an extra \\ before the ?

JSON.parse('["<script>var bob = \\"This is ok\\"</script>", "<script>search.replace(/!|\\\\?)/g, \\"\\")</script>"]')
["<script>var bob = "This is ok"</script>", "<script>search.replace(/!|\?)/g, "")</script>"]