In Perl, how can I tell if a string is a number?

Question

I am using Perl to convert some XML to JSON. If the XML attribute is a number, I don\'t want to put quotes around it so that JSON will treat it as a number and not a string. How

Answer 1

The JSON specification provides fairly clear rules on the format of a number, so the following regex should work:

/^-?(0|([1-9][0-9]*))(\.[0-9]+)?([eE][-+]?[0-9]+)?$/