Question

I want to match this :

• eight(8) alphanumeric characters
• followed by – hyphen
• followed by twentytwo(22) alphanumeric characters, here is what I tried and its not matching :

[8]\w+-[22]\w+

Answer 1

Should be:

\w{8}-\w{22}

[8] matches a single character – the literal 8, and [22] matches one literal 2.

Note that \w also allows the underscore. If that is a problem, use

[a-zA-Z0-9]{8}-[a-zA-Z0-9]{22}

A good tip from Tim, if you want tp capture the pattern from a file or string, you probably want to add \b – word boundary, to avoid partial matching. For example, if you wanted a 2-4 format 12-1234, the first parrent will match 1234-1234567:

\b\w{8}-\w{22}\b