Trying to parse JSON string, unexpected number

Question

I am trying to parse this JSON:

var json = '{"material":"Gummislang 3\/4\" 30 m (utanp\u00e5liggande sk\u00e5p)"}'

I run JSON.parse(json) but i get the error SyntaxError: Unexpected number when doing so. I have tried this in Google Chrome. I don't know what the problem is since I can take the JSON string and put it in any JSON validator and it claims that the JSON is valid. Shouldn't the browser be able to parse it?

Answer 1

You are inserting a JSON object representation into a JavaScript string without properly escaping the representation.

To avoid having to do this, remove the quotes you are adding around the representation, and skip the JSON.parse(json) – the default output from PHP's json_encode() is valid JavaScript when used in this context.

For security, you should specify the JSON_HEX_TAG option if possible. This will prevent cross-site scripting in cases where the JSON might end up inside a document parsed as XML. (And for XML documents, the JSON should be inside a CDATA section as well.)