This is a regex for the special format of a phone number like this:
+[COUNTRY CODE] ([AREA CODE]) [CONNECTION NUMBER][[-[EXTENSION]]]
\+\d{1,3}\s\(\d{2,}\)\s\d{3,}(-\d{1,4})?$
It matches numbers like these:
+49 (30) 227-0
+49 (30) 2270
+49 (170) 1212121
+49 (25715) 777777-102
+1 (206) 555-0100
+44 (113) 496-0000
+44 (20) 7946-0000
Visit regexr.com/68edv to test your own.
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