Regular Expressions 101

^start of line

Negative Lookahead(?!(\d)([.-]?\1)+$)

Group 1(\d)

\da digit

Group 2([.-]?\1)+

+repeats the group contents below at least once:

Character Class[.-]?

?matches at most one character from the set below:

.the literal . (46₁₀ / 56₈ / 2E₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\1the text saved by group 1

$end of line

Group 3(\d{3}[-.]?\d{3}[-.]?\d{4})

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

Character Class[-.]?

?matches at most one character from the set below:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

.the literal . (46₁₀ / 56₈ / 2E₁₆)

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

Character Class[-.]?

?matches at most one character from the set below:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

.the literal . (46₁₀ / 56₈ / 2E₁₆)

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

Global pattern flags

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

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?!(\d)([.-]?\1)+$)(\d{3}[-.]?\d{3}[-.]?\d{4})

New

1111111111
111-111-1111
111.111.1111

112.111.1111
111.112.1111
111.111.1112

767-789-9876
7677899876