Unwanted conversion of select box values from string to Infinity

[danieliser]

We used this to parse a form that includes a select box of mailchimp list ids.

Recently one of our users reported strange issues, on investigation it was found that his list ID was something like this 52e999999

The JSON.parse(value); line is eating this converting it to an integer which in this case is returned as Infinity

I'm guessing for select fields it shouldn't be parsing it as json in general?