Question

I am new to regular expressions and need some help.

How can I turn

string : 7+(4x+2)(3*5)^5
into : 7+(#+#)(3*5)^5

using regular expressions. Is it possible?

basically replace 0-9a-z of string with ( opening 0-9a-z + 0-9a-z ) closing

EDIT

other examples:

string : 3(3+5)^4+8(0+2)
into : 3(#+#)^4+8(#+#)

string : (4+6)
into : (#+#)

string : (4+6)(4+6)
into : (#+#)(#+#)

Answer 1

Try this

(?<=\()\d+[a-z]?\+\d+[a-z]?(?=\))

See it here on Regexr

These two (?<=\() and (?=\)) is a look behind and a look ahead, they ensure, that there is a bracket before and ahead.

\d+[a-z]? is at least one digit followed by one letter.

The + is a special character and needs to be escaped, so \+.

Replace this match with

#+#