Based on jlistf's answer:

( undef, $areacode, $exchange, $line ) = $phn =~
    m|(1-)?\(?(\d{3})\)?-?(\d{3})-(\d{4})|;
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Works on strings such as the following:

212-555-1212
(212)555-1213 
1-(212)-555-1214
1-212-555-1215
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Originally posted as a Categorized Answer.