Regex : Find a number between parentheses

Question

I need a regex who find the number in bold below :

20 (LBDD hello 312312 ) Potato 1651 (98)

20 (LBDD hello 312312 bunny ) Potato 1651 (98)

20 ( 312312 ) Potato 1651 (98)

((\\d+)) find the number 98

I do not know what to do when there are other characters in the parenthesis

Answer 1

This only matches 312312 in the first capture group:

^.*?\([^\d]*(\d+)[^\d]*\).*$

Regexplanation:

^        # Match the start of the line
.*?      # Non-greedy match anything
\(       # Upto the first opening bracket (escaped)
[^\d]*   # Match anything not a digit (zero or more)
(\d+)    # Match a digit string (one or more)
[^\d]*   # Match anything not a digit (zero or more)
\)       # Match closing bracket
.*       # Match the rest of the line
$        # Match the end of the line

See it here .

Answer 2

the following regex should do it

@"\([^\d]*(\d+)[^\d]*\)"

the parenthesis represent a capturing group, and the \\( are escaped parenthesis , which represent the actual parenthesis in your input string.

as a note: depending on what language you impliment your regex in, you may have to escape your escape char, \\ , so be careful of that.

I'd be careful with this though, One of the textbook limitations of regex is that it can't identify properly parenthesized text.