Reuse part of a Regex pattern

Question

Consider this (very simplified) example string:

1aw2,5cx7

As you can see, it is two digit/letter/letter/digit values separated

Answer 1

Try using back referencing, i believe it works something like below to match

1aw2,5cx7

You could use

(\d\w\w\d),\1

See here for reference http://www.regular-expressions.info/backref.html