Regular Expressions 101

Group 1(\()?

?repeats the group contents below at most once:

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

Group 2((?(1)\d{3}(?=\))|\d{3}(?!\))))

Condition(?(1)\d{3}(?=\))|\d{3}(?!\)))

Uses the first branch if group 1 matched

If the condition is true, match this branch:\d{3}(?=\))

\d{3}a digit, repeated exactly 3 times

Positive Lookahead(?=\))

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

Otherwise, match this branch:\d{3}(?!\))

\d{3}a digit, repeated exactly 3 times

Negative Lookahead(?!\))

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

\)?optionally matches the literal ) (41₁₀ / 51₈ / 29₁₆)

Character Class[ -.]?

?matches at most one character from the set below:

-.one character from (32₁₀) to . (46₁₀)

Group 3(\d{3})

\d{3}a digit, repeated exactly 3 times

Character Class[ -.]?

?matches at most one character from the set below:

-.one character from (32₁₀) to . (46₁₀)

Group 4(\d{4})

\d{4}a digit, repeated exactly 4 times

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

(\()?((?(1)\d{3}(?=\))|\d{3}(?!\))))\)?[ -.]?(\d{3})[ -.]?(\d{4})

New

(123)456-7890 (321)-654-0987
(111) 111-1111
222-222-2222
(333)333.3333
(444).444.4444
blah blah blah (555) 555.5555
666.666.6666 random text

(\2)\3-\4