regex101: JavaScript Match Workspace

^start of line

\+?optionally matches the literal + (43₁₀ / 53₈ / 2B₁₆)

Negative Lookahead(?![^ \n-]*[ -]{2})

Negated Character Class[^ \n-]*

*matches any number of characters outside the set below:

the literal (32₁₀ / 40₈ / 20₁₆)

\na line-feed (newline) character (ASCII 10)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Character Class[ -]{2}

{2}matches exactly 2 characters from the set below:

the literal (32₁₀ / 40₈ / 20₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Positive Lookahead(?=(?:[ -]*\d){10,12}$)

Non-Capturing Group(?:[ -]*\d){10,12}

{10,12}repeats the group contents below between 10 and 12 times:

Character Class[ -]*

*matches any number of characters from the set below:

the literal (32₁₀ / 40₈ / 20₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\da digit

$end of line

\da digit

Character Class[\d -]*

*matches any number of characters from the set below:

\da digit

the literal (32₁₀ / 40₈ / 20₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\da digit

$end of line

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

Search reference

Regular Expression

^\+?(?![^ \n-]*[ -]{2})(?=(?:[ -]*\d){10,12}$)\d[\d -]*\d$

Test String
New

+12 1234567890
+12 12 345 567 89
+12 123-455-6789
+9712345567

Additional good
9712345567

Additional bad
+9712345- - 567
+9712345678 
 +9712345678
+ 9712345678
+97--12345678

+1234567890123
+123456789

The regex is for validating phone numbers so it should have minimum length 10 digits and maximum length of 12 digits except special symbols like +, - and space.
Plus sign only allowed at start. I tried below regex but not working for me.

Regular Expression

Test StringNew

Test String
New