Question

I’m looking for a single line regular expression which matches a pattern with optional parentheses. When the parentheses are present they should not be included in the matched pattern.

The following bold text demonstrates what should / shouldn’t match:

Should Match:

“Title Description (AAA123)”

“(ABC000) Title Description”

“Title Description DEF999“

“Title – RST321 – Description”

Shouldn’t Match:

“Title Description AB123”

“Title Description CCC456a”

“Title Description (ABE999c)”

Answer 1

Try this regex:

\b[a-zA-Z]{3}\d{3}\b

This matches:

# \b          - A word boundary,
# [a-zA-Z]{3} - followed by 3 letters,
# \d{3}       - followed by 3 digits,
# \b          - followed by a word boundary.

The regex doesn’t care about parentheses, like requested, but doesn’t match strings that are too long.