Regular Expressions 101

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`
^\+\d{1,3}\s*\(?\d{3,6}\)?\s*[\d\-\s]{4,9}$
`
gm
^ asserts position at start of a line
\+ matches the character + with index 4310 (2B16 or 538) literally (case sensitive)
\d
matches a digit (equivalent to [0-9])
{1,3} matches the previous token between 1 and 3 times, as many times as possible, giving back as needed (greedy)
\s
matches any whitespace character (equivalent to [\r\n\t\f\v ])
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
\(
matches the character ( with index 4010 (2816 or 508) literally (case sensitive)
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
\d
matches a digit (equivalent to [0-9])
{3,6} matches the previous token between 3 and 6 times, as many times as possible, giving back as needed (greedy)
\)
matches the character ) with index 4110 (2916 or 518) literally (case sensitive)
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
\s
matches any whitespace character (equivalent to [\r\n\t\f\v ])
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
Match a single character present in the list below
[\d\-\s]
{4,9} matches the previous token between 4 and 9 times, as many times as possible, giving back as needed (greedy)
\d matches a digit (equivalent to [0-9])
\- matches the character - with index 4510 (2D16 or 558) literally (case sensitive)
\s matches any whitespace character (equivalent to [\r\n\t\f\v ])
$ asserts position at the end of a line
Global pattern flags
g modifier: global. All matches (don't return after first match)
m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)
Your regular expression does not match the subject string.

Regular Expression
No Match

`
`
gm

Test String